Merge pull request #25034 from ziglang/lzma

std.compress: update lzma, lzma2, and xz to new I/O API
This commit is contained in:
Andrew Kelley 2025-08-27 06:49:45 -07:00 committed by GitHub
commit 50edad37ba
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
13 changed files with 1470 additions and 1612 deletions

View file

@ -2,89 +2,759 @@ const std = @import("../std.zig");
const math = std.math;
const mem = std.mem;
const Allocator = std.mem.Allocator;
const assert = std.debug.assert;
const ArrayList = std.ArrayList;
const Writer = std.Io.Writer;
const Reader = std.Io.Reader;
pub const decode = @import("lzma/decode.zig");
pub const RangeDecoder = struct {
range: u32,
code: u32,
pub fn decompress(
allocator: Allocator,
reader: anytype,
) !Decompress(@TypeOf(reader)) {
return decompressWithOptions(allocator, reader, .{});
pub fn init(reader: *Reader) !RangeDecoder {
var counter: u64 = 0;
return initCounting(reader, &counter);
}
pub fn decompressWithOptions(
allocator: Allocator,
reader: anytype,
options: decode.Options,
) !Decompress(@TypeOf(reader)) {
const params = try decode.Params.readHeader(reader, options);
return Decompress(@TypeOf(reader)).init(allocator, reader, params, options.memlimit);
}
pub fn Decompress(comptime ReaderType: type) type {
return struct {
const Self = @This();
pub const Error =
ReaderType.Error ||
Allocator.Error ||
error{ CorruptInput, EndOfStream, Overflow };
pub const Reader = std.io.GenericReader(*Self, Error, read);
allocator: Allocator,
in_reader: ReaderType,
to_read: std.ArrayListUnmanaged(u8),
buffer: decode.lzbuffer.LzCircularBuffer,
decoder: decode.rangecoder.RangeDecoder,
state: decode.DecoderState,
pub fn init(allocator: Allocator, source: ReaderType, params: decode.Params, memlimit: ?usize) !Self {
return Self{
.allocator = allocator,
.in_reader = source,
.to_read = .{},
.buffer = decode.lzbuffer.LzCircularBuffer.init(params.dict_size, memlimit orelse math.maxInt(usize)),
.decoder = try decode.rangecoder.RangeDecoder.init(source),
.state = try decode.DecoderState.init(allocator, params.properties, params.unpacked_size),
pub fn initCounting(reader: *Reader, n_read: *u64) !RangeDecoder {
const reserved = try reader.takeByte();
n_read.* += 1;
if (reserved != 0) return error.InvalidRangeCode;
const code = try reader.takeInt(u32, .big);
n_read.* += 4;
return .{
.range = 0xFFFF_FFFF,
.code = code,
};
}
pub fn reader(self: *Self) Reader {
return .{ .context = self };
pub fn isFinished(self: RangeDecoder) bool {
return self.code == 0;
}
pub fn deinit(self: *Self) void {
self.to_read.deinit(self.allocator);
self.buffer.deinit(self.allocator);
self.state.deinit(self.allocator);
fn normalize(self: *RangeDecoder, reader: *Reader, n_read: *u64) !void {
if (self.range < 0x0100_0000) {
self.range <<= 8;
self.code = (self.code << 8) ^ @as(u32, try reader.takeByte());
n_read.* += 1;
}
}
fn getBit(self: *RangeDecoder, reader: *Reader, n_read: *u64) !bool {
self.range >>= 1;
const bit = self.code >= self.range;
if (bit) self.code -= self.range;
try self.normalize(reader, n_read);
return bit;
}
pub fn get(self: *RangeDecoder, reader: *Reader, count: usize, n_read: *u64) !u32 {
var result: u32 = 0;
for (0..count) |_| {
result = (result << 1) ^ @intFromBool(try self.getBit(reader, n_read));
}
return result;
}
pub fn decodeBit(self: *RangeDecoder, reader: *Reader, prob: *u16, n_read: *u64) !bool {
const bound = (self.range >> 11) * prob.*;
if (self.code < bound) {
prob.* += (0x800 - prob.*) >> 5;
self.range = bound;
try self.normalize(reader, n_read);
return false;
} else {
prob.* -= prob.* >> 5;
self.code -= bound;
self.range -= bound;
try self.normalize(reader, n_read);
return true;
}
}
fn parseBitTree(
self: *RangeDecoder,
reader: *Reader,
num_bits: u5,
probs: []u16,
n_read: *u64,
) !u32 {
var tmp: u32 = 1;
var i: @TypeOf(num_bits) = 0;
while (i < num_bits) : (i += 1) {
const bit = try self.decodeBit(reader, &probs[tmp], n_read);
tmp = (tmp << 1) ^ @intFromBool(bit);
}
return tmp - (@as(u32, 1) << num_bits);
}
pub fn parseReverseBitTree(
self: *RangeDecoder,
reader: *Reader,
num_bits: u5,
probs: []u16,
offset: usize,
n_read: *u64,
) !u32 {
var result: u32 = 0;
var tmp: usize = 1;
var i: @TypeOf(num_bits) = 0;
while (i < num_bits) : (i += 1) {
const bit = @intFromBool(try self.decodeBit(reader, &probs[offset + tmp], n_read));
tmp = (tmp << 1) ^ bit;
result ^= @as(u32, bit) << i;
}
return result;
}
};
pub const Decode = struct {
properties: Properties,
literal_probs: Vec2d,
pos_slot_decoder: [4]BitTree(6),
align_decoder: BitTree(4),
pos_decoders: [115]u16,
is_match: [192]u16,
is_rep: [12]u16,
is_rep_g0: [12]u16,
is_rep_g1: [12]u16,
is_rep_g2: [12]u16,
is_rep_0long: [192]u16,
state: usize,
rep: [4]usize,
len_decoder: LenDecoder,
rep_len_decoder: LenDecoder,
pub fn init(gpa: Allocator, properties: Properties) !Decode {
return .{
.properties = properties,
.literal_probs = try Vec2d.init(gpa, 0x400, @as(usize, 1) << (properties.lc + properties.lp), 0x300),
.pos_slot_decoder = @splat(.{}),
.align_decoder = .{},
.pos_decoders = @splat(0x400),
.is_match = @splat(0x400),
.is_rep = @splat(0x400),
.is_rep_g0 = @splat(0x400),
.is_rep_g1 = @splat(0x400),
.is_rep_g2 = @splat(0x400),
.is_rep_0long = @splat(0x400),
.state = 0,
.rep = @splat(0),
.len_decoder = .{},
.rep_len_decoder = .{},
};
}
pub fn deinit(self: *Decode, gpa: Allocator) void {
self.literal_probs.deinit(gpa);
self.* = undefined;
}
pub fn read(self: *Self, output: []u8) Error!usize {
const writer = self.to_read.writer(self.allocator);
while (self.to_read.items.len < output.len) {
switch (try self.state.process(self.allocator, self.in_reader, writer, &self.buffer, &self.decoder)) {
.continue_ => {},
.finished => {
try self.buffer.finish(writer);
pub fn resetState(self: *Decode, gpa: Allocator, new_props: Properties) !void {
new_props.validate();
if (self.properties.lc + self.properties.lp == new_props.lc + new_props.lp) {
self.literal_probs.fill(0x400);
} else {
self.literal_probs.deinit(gpa);
self.literal_probs = try Vec2d.init(gpa, 0x400, @as(usize, 1) << (new_props.lc + new_props.lp), 0x300);
}
self.properties = new_props;
for (&self.pos_slot_decoder) |*t| t.reset();
self.align_decoder.reset();
self.pos_decoders = @splat(0x400);
self.is_match = @splat(0x400);
self.is_rep = @splat(0x400);
self.is_rep_g0 = @splat(0x400);
self.is_rep_g1 = @splat(0x400);
self.is_rep_g2 = @splat(0x400);
self.is_rep_0long = @splat(0x400);
self.state = 0;
self.rep = @splat(0);
self.len_decoder.reset();
self.rep_len_decoder.reset();
}
pub fn process(
self: *Decode,
reader: *Reader,
allocating: *Writer.Allocating,
/// `CircularBuffer` or `std.compress.lzma2.AccumBuffer`.
buffer: anytype,
decoder: *RangeDecoder,
n_read: *u64,
) !ProcessingStatus {
const gpa = allocating.allocator;
const writer = &allocating.writer;
const pos_state = buffer.len & ((@as(usize, 1) << self.properties.pb) - 1);
if (!try decoder.decodeBit(reader, &self.is_match[(self.state << 4) + pos_state], n_read)) {
const byte: u8 = try self.decodeLiteral(reader, buffer, decoder, n_read);
try buffer.appendLiteral(gpa, byte, writer);
self.state = if (self.state < 4)
0
else if (self.state < 10)
self.state - 3
else
self.state - 6;
return .more;
}
var len: usize = undefined;
if (try decoder.decodeBit(reader, &self.is_rep[self.state], n_read)) {
if (!try decoder.decodeBit(reader, &self.is_rep_g0[self.state], n_read)) {
if (!try decoder.decodeBit(reader, &self.is_rep_0long[(self.state << 4) + pos_state], n_read)) {
self.state = if (self.state < 7) 9 else 11;
const dist = self.rep[0] + 1;
try buffer.appendLz(gpa, 1, dist, writer);
return .more;
}
} else {
const idx: usize = if (!try decoder.decodeBit(reader, &self.is_rep_g1[self.state], n_read))
1
else if (!try decoder.decodeBit(reader, &self.is_rep_g2[self.state], n_read))
2
else
3;
const dist = self.rep[idx];
var i = idx;
while (i > 0) : (i -= 1) {
self.rep[i] = self.rep[i - 1];
}
self.rep[0] = dist;
}
len = try self.rep_len_decoder.decode(reader, decoder, pos_state, n_read);
self.state = if (self.state < 7) 8 else 11;
} else {
self.rep[3] = self.rep[2];
self.rep[2] = self.rep[1];
self.rep[1] = self.rep[0];
len = try self.len_decoder.decode(reader, decoder, pos_state, n_read);
self.state = if (self.state < 7) 7 else 10;
const rep_0 = try self.decodeDistance(reader, decoder, len, n_read);
self.rep[0] = rep_0;
if (self.rep[0] == 0xFFFF_FFFF) {
if (decoder.isFinished()) {
return .finished;
}
return error.CorruptInput;
}
}
len += 2;
const dist = self.rep[0] + 1;
try buffer.appendLz(gpa, len, dist, writer);
return .more;
}
fn decodeLiteral(
self: *Decode,
reader: *Reader,
/// `CircularBuffer` or `std.compress.lzma2.AccumBuffer`.
buffer: anytype,
decoder: *RangeDecoder,
n_read: *u64,
) !u8 {
const def_prev_byte = 0;
const prev_byte = @as(usize, buffer.lastOr(def_prev_byte));
var result: usize = 1;
const lit_state = ((buffer.len & ((@as(usize, 1) << self.properties.lp) - 1)) << self.properties.lc) +
(prev_byte >> (8 - self.properties.lc));
const probs = try self.literal_probs.get(lit_state);
if (self.state >= 7) {
var match_byte = @as(usize, try buffer.lastN(self.rep[0] + 1));
while (result < 0x100) {
const match_bit = (match_byte >> 7) & 1;
match_byte <<= 1;
const bit = @intFromBool(try decoder.decodeBit(
reader,
&probs[((@as(usize, 1) + match_bit) << 8) + result],
n_read,
));
result = (result << 1) ^ bit;
if (match_bit != bit) {
break;
},
}
}
const input = self.to_read.items;
const n = @min(input.len, output.len);
@memcpy(output[0..n], input[0..n]);
std.mem.copyForwards(u8, input[0 .. input.len - n], input[n..]);
self.to_read.shrinkRetainingCapacity(input.len - n);
return n;
}
while (result < 0x100) {
result = (result << 1) ^ @intFromBool(try decoder.decodeBit(reader, &probs[result], n_read));
}
return @truncate(result - 0x100);
}
fn decodeDistance(
self: *Decode,
reader: *Reader,
decoder: *RangeDecoder,
length: usize,
n_read: *u64,
) !usize {
const len_state = if (length > 3) 3 else length;
const pos_slot: usize = try self.pos_slot_decoder[len_state].parse(reader, decoder, n_read);
if (pos_slot < 4) return pos_slot;
const num_direct_bits = @as(u5, @intCast((pos_slot >> 1) - 1));
var result = (2 ^ (pos_slot & 1)) << num_direct_bits;
if (pos_slot < 14) {
result += try decoder.parseReverseBitTree(
reader,
num_direct_bits,
&self.pos_decoders,
result - pos_slot,
n_read,
);
} else {
result += @as(usize, try decoder.get(reader, num_direct_bits - 4, n_read)) << 4;
result += try self.align_decoder.parseReverse(reader, decoder, n_read);
}
return result;
}
/// A circular buffer for LZ sequences
pub const CircularBuffer = struct {
/// Circular buffer
buf: ArrayList(u8),
/// Length of the buffer
dict_size: usize,
/// Buffer memory limit
mem_limit: usize,
/// Current position
cursor: usize,
/// Total number of bytes sent through the buffer
len: usize,
pub fn init(dict_size: usize, mem_limit: usize) CircularBuffer {
return .{
.buf = .{},
.dict_size = dict_size,
.mem_limit = mem_limit,
.cursor = 0,
.len = 0,
};
}
pub fn get(self: CircularBuffer, index: usize) u8 {
return if (0 <= index and index < self.buf.items.len) self.buf.items[index] else 0;
}
pub fn set(self: *CircularBuffer, gpa: Allocator, index: usize, value: u8) !void {
if (index >= self.mem_limit) {
return error.CorruptInput;
}
try self.buf.ensureTotalCapacity(gpa, index + 1);
while (self.buf.items.len < index) {
self.buf.appendAssumeCapacity(0);
}
self.buf.appendAssumeCapacity(value);
}
/// Retrieve the last byte or return a default
pub fn lastOr(self: CircularBuffer, lit: u8) u8 {
return if (self.len == 0)
lit
else
self.get((self.dict_size + self.cursor - 1) % self.dict_size);
}
/// Retrieve the n-th last byte
pub fn lastN(self: CircularBuffer, dist: usize) !u8 {
if (dist > self.dict_size or dist > self.len) {
return error.CorruptInput;
}
const offset = (self.dict_size + self.cursor - dist) % self.dict_size;
return self.get(offset);
}
/// Append a literal
pub fn appendLiteral(
self: *CircularBuffer,
gpa: Allocator,
lit: u8,
writer: *Writer,
) !void {
try self.set(gpa, self.cursor, lit);
self.cursor += 1;
self.len += 1;
// Flush the circular buffer to the output
if (self.cursor == self.dict_size) {
try writer.writeAll(self.buf.items);
self.cursor = 0;
}
}
/// Fetch an LZ sequence (length, distance) from inside the buffer
pub fn appendLz(
self: *CircularBuffer,
gpa: Allocator,
len: usize,
dist: usize,
writer: *Writer,
) !void {
if (dist > self.dict_size or dist > self.len) {
return error.CorruptInput;
}
var offset = (self.dict_size + self.cursor - dist) % self.dict_size;
var i: usize = 0;
while (i < len) : (i += 1) {
const x = self.get(offset);
try self.appendLiteral(gpa, x, writer);
offset += 1;
if (offset == self.dict_size) {
offset = 0;
}
}
}
pub fn finish(self: *CircularBuffer, writer: *Writer) !void {
if (self.cursor > 0) {
try writer.writeAll(self.buf.items[0..self.cursor]);
self.cursor = 0;
}
}
pub fn deinit(self: *CircularBuffer, gpa: Allocator) void {
self.buf.deinit(gpa);
self.* = undefined;
}
};
pub fn BitTree(comptime num_bits: usize) type {
return struct {
probs: [1 << num_bits]u16 = @splat(0x400),
pub fn parse(self: *@This(), reader: *Reader, decoder: *RangeDecoder, n_read: *u64) !u32 {
return decoder.parseBitTree(reader, num_bits, &self.probs, n_read);
}
pub fn parseReverse(
self: *@This(),
reader: *Reader,
decoder: *RangeDecoder,
n_read: *u64,
) !u32 {
return decoder.parseReverseBitTree(reader, num_bits, &self.probs, 0, n_read);
}
pub fn reset(self: *@This()) void {
@memset(&self.probs, 0x400);
}
};
}
pub const LenDecoder = struct {
choice: u16 = 0x400,
choice2: u16 = 0x400,
low_coder: [16]BitTree(3) = @splat(.{}),
mid_coder: [16]BitTree(3) = @splat(.{}),
high_coder: BitTree(8) = .{},
pub fn decode(
self: *LenDecoder,
reader: *Reader,
decoder: *RangeDecoder,
pos_state: usize,
n_read: *u64,
) !usize {
if (!try decoder.decodeBit(reader, &self.choice, n_read)) {
return @as(usize, try self.low_coder[pos_state].parse(reader, decoder, n_read));
} else if (!try decoder.decodeBit(reader, &self.choice2, n_read)) {
return @as(usize, try self.mid_coder[pos_state].parse(reader, decoder, n_read)) + 8;
} else {
return @as(usize, try self.high_coder.parse(reader, decoder, n_read)) + 16;
}
}
pub fn reset(self: *LenDecoder) void {
self.choice = 0x400;
self.choice2 = 0x400;
for (&self.low_coder) |*t| t.reset();
for (&self.mid_coder) |*t| t.reset();
self.high_coder.reset();
}
};
pub const Vec2d = struct {
data: []u16,
cols: usize,
pub fn init(gpa: Allocator, value: u16, w: usize, h: usize) !Vec2d {
const len = try math.mul(usize, w, h);
const data = try gpa.alloc(u16, len);
@memset(data, value);
return .{
.data = data,
.cols = h,
};
}
pub fn deinit(v: *Vec2d, gpa: Allocator) void {
gpa.free(v.data);
v.* = undefined;
}
pub fn fill(v: *Vec2d, value: u16) void {
@memset(v.data, value);
}
fn get(v: Vec2d, row: usize) ![]u16 {
const start_row = try math.mul(usize, row, v.cols);
const end_row = try math.add(usize, start_row, v.cols);
return v.data[start_row..end_row];
}
};
pub const Options = struct {
unpacked_size: UnpackedSize = .read_from_header,
mem_limit: ?usize = null,
allow_incomplete: bool = false,
};
pub const UnpackedSize = union(enum) {
read_from_header,
read_header_but_use_provided: ?u64,
use_provided: ?u64,
};
const ProcessingStatus = enum {
more,
finished,
};
pub const Properties = struct {
lc: u4,
lp: u3,
pb: u3,
fn validate(self: Properties) void {
assert(self.lc <= 8);
assert(self.lp <= 4);
assert(self.pb <= 4);
}
};
pub const Params = struct {
properties: Properties,
dict_size: u32,
unpacked_size: ?u64,
pub fn readHeader(reader: *Reader, options: Options) !Params {
var props = try reader.takeByte();
if (props >= 225) return error.CorruptInput;
const lc: u4 = @intCast(props % 9);
props /= 9;
const lp: u3 = @intCast(props % 5);
props /= 5;
const pb: u3 = @intCast(props);
const dict_size_provided = try reader.takeInt(u32, .little);
const dict_size = @max(0x1000, dict_size_provided);
const unpacked_size = switch (options.unpacked_size) {
.read_from_header => blk: {
const unpacked_size_provided = try reader.takeInt(u64, .little);
const marker_mandatory = unpacked_size_provided == 0xFFFF_FFFF_FFFF_FFFF;
break :blk if (marker_mandatory) null else unpacked_size_provided;
},
.read_header_but_use_provided => |x| blk: {
_ = try reader.takeInt(u64, .little);
break :blk x;
},
.use_provided => |x| x,
};
return .{
.properties = .{ .lc = lc, .lp = lp, .pb = pb },
.dict_size = dict_size,
.unpacked_size = unpacked_size,
};
}
};
};
pub const Decompress = struct {
gpa: Allocator,
input: *Reader,
reader: Reader,
buffer: Decode.CircularBuffer,
range_decoder: RangeDecoder,
decode: Decode,
err: ?Error,
unpacked_size: ?u64,
pub const Error = error{
OutOfMemory,
ReadFailed,
CorruptInput,
DecompressedSizeMismatch,
EndOfStream,
Overflow,
};
/// Takes ownership of `buffer` which may be resized with `gpa`.
///
/// LZMA was explicitly designed to take advantage of large heap memory
/// being available, with a dictionary size anywhere from 4K to 4G. Thus,
/// this API dynamically allocates the dictionary as-needed.
pub fn initParams(
input: *Reader,
gpa: Allocator,
buffer: []u8,
params: Decode.Params,
mem_limit: usize,
) !Decompress {
return .{
.gpa = gpa,
.input = input,
.buffer = Decode.CircularBuffer.init(params.dict_size, mem_limit),
.range_decoder = try RangeDecoder.init(input),
.decode = try Decode.init(gpa, params.properties),
.reader = .{
.buffer = buffer,
.vtable = &.{
.readVec = readVec,
.stream = stream,
.discard = discard,
},
.seek = 0,
.end = 0,
},
.err = null,
.unpacked_size = params.unpacked_size,
};
}
/// Takes ownership of `buffer` which may be resized with `gpa`.
///
/// LZMA was explicitly designed to take advantage of large heap memory
/// being available, with a dictionary size anywhere from 4K to 4G. Thus,
/// this API dynamically allocates the dictionary as-needed.
pub fn initOptions(
input: *Reader,
gpa: Allocator,
buffer: []u8,
options: Decode.Options,
mem_limit: usize,
) !Decompress {
const params = try Decode.Params.readHeader(input, options);
return initParams(input, gpa, buffer, params, mem_limit);
}
/// Reclaim ownership of the buffer passed to `init`.
pub fn takeBuffer(d: *Decompress) []u8 {
const buffer = d.reader.buffer;
d.reader.buffer = &.{};
return buffer;
}
pub fn deinit(d: *Decompress) void {
const gpa = d.gpa;
gpa.free(d.reader.buffer);
d.buffer.deinit(gpa);
d.decode.deinit(gpa);
d.* = undefined;
}
fn readVec(r: *Reader, data: [][]u8) Reader.Error!usize {
_ = data;
return readIndirect(r);
}
fn stream(r: *Reader, w: *Writer, limit: std.Io.Limit) Reader.StreamError!usize {
_ = w;
_ = limit;
return readIndirect(r);
}
fn discard(r: *Reader, limit: std.Io.Limit) Reader.Error!usize {
const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
_ = d;
_ = limit;
@panic("TODO");
}
fn readIndirect(r: *Reader) Reader.Error!usize {
const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
const gpa = d.gpa;
var allocating = Writer.Allocating.initOwnedSlice(gpa, r.buffer);
allocating.writer.end = r.end;
defer {
r.buffer = allocating.writer.buffer;
r.end = allocating.writer.end;
}
if (d.decode.state == math.maxInt(usize)) return error.EndOfStream;
process_next: {
if (d.unpacked_size) |unpacked_size| {
if (d.buffer.len >= unpacked_size) break :process_next;
} else if (d.range_decoder.isFinished()) {
break :process_next;
}
var n_read: u64 = 0;
switch (d.decode.process(d.input, &allocating, &d.buffer, &d.range_decoder, &n_read) catch |err| switch (err) {
error.WriteFailed => {
d.err = error.OutOfMemory;
return error.ReadFailed;
},
error.EndOfStream => {
d.err = error.EndOfStream;
return error.ReadFailed;
},
else => |e| {
d.err = e;
return error.ReadFailed;
},
}) {
.more => return 0,
.finished => break :process_next,
}
}
if (d.unpacked_size) |unpacked_size| {
if (d.buffer.len != unpacked_size) {
d.err = error.DecompressedSizeMismatch;
return error.ReadFailed;
}
}
d.buffer.finish(&allocating.writer) catch |err| switch (err) {
error.WriteFailed => {
d.err = error.OutOfMemory;
return error.ReadFailed;
},
};
d.decode.state = math.maxInt(usize);
return 0;
}
};
test {
_ = @import("lzma/test.zig");
_ = @import("lzma/vec2d.zig");
}

View file

@ -1,379 +0,0 @@
const std = @import("../../std.zig");
const assert = std.debug.assert;
const math = std.math;
const Allocator = std.mem.Allocator;
pub const lzbuffer = @import("decode/lzbuffer.zig");
pub const rangecoder = @import("decode/rangecoder.zig");
const LzCircularBuffer = lzbuffer.LzCircularBuffer;
const BitTree = rangecoder.BitTree;
const LenDecoder = rangecoder.LenDecoder;
const RangeDecoder = rangecoder.RangeDecoder;
const Vec2D = @import("vec2d.zig").Vec2D;
pub const Options = struct {
unpacked_size: UnpackedSize = .read_from_header,
memlimit: ?usize = null,
allow_incomplete: bool = false,
};
pub const UnpackedSize = union(enum) {
read_from_header,
read_header_but_use_provided: ?u64,
use_provided: ?u64,
};
const ProcessingStatus = enum {
continue_,
finished,
};
pub const Properties = struct {
lc: u4,
lp: u3,
pb: u3,
fn validate(self: Properties) void {
assert(self.lc <= 8);
assert(self.lp <= 4);
assert(self.pb <= 4);
}
};
pub const Params = struct {
properties: Properties,
dict_size: u32,
unpacked_size: ?u64,
pub fn readHeader(reader: anytype, options: Options) !Params {
var props = try reader.readByte();
if (props >= 225) {
return error.CorruptInput;
}
const lc = @as(u4, @intCast(props % 9));
props /= 9;
const lp = @as(u3, @intCast(props % 5));
props /= 5;
const pb = @as(u3, @intCast(props));
const dict_size_provided = try reader.readInt(u32, .little);
const dict_size = @max(0x1000, dict_size_provided);
const unpacked_size = switch (options.unpacked_size) {
.read_from_header => blk: {
const unpacked_size_provided = try reader.readInt(u64, .little);
const marker_mandatory = unpacked_size_provided == 0xFFFF_FFFF_FFFF_FFFF;
break :blk if (marker_mandatory)
null
else
unpacked_size_provided;
},
.read_header_but_use_provided => |x| blk: {
_ = try reader.readInt(u64, .little);
break :blk x;
},
.use_provided => |x| x,
};
return Params{
.properties = Properties{ .lc = lc, .lp = lp, .pb = pb },
.dict_size = dict_size,
.unpacked_size = unpacked_size,
};
}
};
pub const DecoderState = struct {
lzma_props: Properties,
unpacked_size: ?u64,
literal_probs: Vec2D(u16),
pos_slot_decoder: [4]BitTree(6),
align_decoder: BitTree(4),
pos_decoders: [115]u16,
is_match: [192]u16,
is_rep: [12]u16,
is_rep_g0: [12]u16,
is_rep_g1: [12]u16,
is_rep_g2: [12]u16,
is_rep_0long: [192]u16,
state: usize,
rep: [4]usize,
len_decoder: LenDecoder,
rep_len_decoder: LenDecoder,
pub fn init(
allocator: Allocator,
lzma_props: Properties,
unpacked_size: ?u64,
) !DecoderState {
return .{
.lzma_props = lzma_props,
.unpacked_size = unpacked_size,
.literal_probs = try Vec2D(u16).init(allocator, 0x400, .{ @as(usize, 1) << (lzma_props.lc + lzma_props.lp), 0x300 }),
.pos_slot_decoder = @splat(.{}),
.align_decoder = .{},
.pos_decoders = @splat(0x400),
.is_match = @splat(0x400),
.is_rep = @splat(0x400),
.is_rep_g0 = @splat(0x400),
.is_rep_g1 = @splat(0x400),
.is_rep_g2 = @splat(0x400),
.is_rep_0long = @splat(0x400),
.state = 0,
.rep = @splat(0),
.len_decoder = .{},
.rep_len_decoder = .{},
};
}
pub fn deinit(self: *DecoderState, allocator: Allocator) void {
self.literal_probs.deinit(allocator);
self.* = undefined;
}
pub fn resetState(self: *DecoderState, allocator: Allocator, new_props: Properties) !void {
new_props.validate();
if (self.lzma_props.lc + self.lzma_props.lp == new_props.lc + new_props.lp) {
self.literal_probs.fill(0x400);
} else {
self.literal_probs.deinit(allocator);
self.literal_probs = try Vec2D(u16).init(allocator, 0x400, .{ @as(usize, 1) << (new_props.lc + new_props.lp), 0x300 });
}
self.lzma_props = new_props;
for (&self.pos_slot_decoder) |*t| t.reset();
self.align_decoder.reset();
self.pos_decoders = @splat(0x400);
self.is_match = @splat(0x400);
self.is_rep = @splat(0x400);
self.is_rep_g0 = @splat(0x400);
self.is_rep_g1 = @splat(0x400);
self.is_rep_g2 = @splat(0x400);
self.is_rep_0long = @splat(0x400);
self.state = 0;
self.rep = @splat(0);
self.len_decoder.reset();
self.rep_len_decoder.reset();
}
fn processNextInner(
self: *DecoderState,
allocator: Allocator,
reader: anytype,
writer: anytype,
buffer: anytype,
decoder: *RangeDecoder,
update: bool,
) !ProcessingStatus {
const pos_state = buffer.len & ((@as(usize, 1) << self.lzma_props.pb) - 1);
if (!try decoder.decodeBit(
reader,
&self.is_match[(self.state << 4) + pos_state],
update,
)) {
const byte: u8 = try self.decodeLiteral(reader, buffer, decoder, update);
if (update) {
try buffer.appendLiteral(allocator, byte, writer);
self.state = if (self.state < 4)
0
else if (self.state < 10)
self.state - 3
else
self.state - 6;
}
return .continue_;
}
var len: usize = undefined;
if (try decoder.decodeBit(reader, &self.is_rep[self.state], update)) {
if (!try decoder.decodeBit(reader, &self.is_rep_g0[self.state], update)) {
if (!try decoder.decodeBit(
reader,
&self.is_rep_0long[(self.state << 4) + pos_state],
update,
)) {
if (update) {
self.state = if (self.state < 7) 9 else 11;
const dist = self.rep[0] + 1;
try buffer.appendLz(allocator, 1, dist, writer);
}
return .continue_;
}
} else {
const idx: usize = if (!try decoder.decodeBit(reader, &self.is_rep_g1[self.state], update))
1
else if (!try decoder.decodeBit(reader, &self.is_rep_g2[self.state], update))
2
else
3;
if (update) {
const dist = self.rep[idx];
var i = idx;
while (i > 0) : (i -= 1) {
self.rep[i] = self.rep[i - 1];
}
self.rep[0] = dist;
}
}
len = try self.rep_len_decoder.decode(reader, decoder, pos_state, update);
if (update) {
self.state = if (self.state < 7) 8 else 11;
}
} else {
if (update) {
self.rep[3] = self.rep[2];
self.rep[2] = self.rep[1];
self.rep[1] = self.rep[0];
}
len = try self.len_decoder.decode(reader, decoder, pos_state, update);
if (update) {
self.state = if (self.state < 7) 7 else 10;
}
const rep_0 = try self.decodeDistance(reader, decoder, len, update);
if (update) {
self.rep[0] = rep_0;
if (self.rep[0] == 0xFFFF_FFFF) {
if (decoder.isFinished()) {
return .finished;
}
return error.CorruptInput;
}
}
}
if (update) {
len += 2;
const dist = self.rep[0] + 1;
try buffer.appendLz(allocator, len, dist, writer);
}
return .continue_;
}
fn processNext(
self: *DecoderState,
allocator: Allocator,
reader: anytype,
writer: anytype,
buffer: anytype,
decoder: *RangeDecoder,
) !ProcessingStatus {
return self.processNextInner(allocator, reader, writer, buffer, decoder, true);
}
pub fn process(
self: *DecoderState,
allocator: Allocator,
reader: anytype,
writer: anytype,
buffer: anytype,
decoder: *RangeDecoder,
) !ProcessingStatus {
process_next: {
if (self.unpacked_size) |unpacked_size| {
if (buffer.len >= unpacked_size) {
break :process_next;
}
} else if (decoder.isFinished()) {
break :process_next;
}
switch (try self.processNext(allocator, reader, writer, buffer, decoder)) {
.continue_ => return .continue_,
.finished => break :process_next,
}
}
if (self.unpacked_size) |unpacked_size| {
if (buffer.len != unpacked_size) {
return error.CorruptInput;
}
}
return .finished;
}
fn decodeLiteral(
self: *DecoderState,
reader: anytype,
buffer: anytype,
decoder: *RangeDecoder,
update: bool,
) !u8 {
const def_prev_byte = 0;
const prev_byte = @as(usize, buffer.lastOr(def_prev_byte));
var result: usize = 1;
const lit_state = ((buffer.len & ((@as(usize, 1) << self.lzma_props.lp) - 1)) << self.lzma_props.lc) +
(prev_byte >> (8 - self.lzma_props.lc));
const probs = try self.literal_probs.getMut(lit_state);
if (self.state >= 7) {
var match_byte = @as(usize, try buffer.lastN(self.rep[0] + 1));
while (result < 0x100) {
const match_bit = (match_byte >> 7) & 1;
match_byte <<= 1;
const bit = @intFromBool(try decoder.decodeBit(
reader,
&probs[((@as(usize, 1) + match_bit) << 8) + result],
update,
));
result = (result << 1) ^ bit;
if (match_bit != bit) {
break;
}
}
}
while (result < 0x100) {
result = (result << 1) ^ @intFromBool(try decoder.decodeBit(reader, &probs[result], update));
}
return @as(u8, @truncate(result - 0x100));
}
fn decodeDistance(
self: *DecoderState,
reader: anytype,
decoder: *RangeDecoder,
length: usize,
update: bool,
) !usize {
const len_state = if (length > 3) 3 else length;
const pos_slot = @as(usize, try self.pos_slot_decoder[len_state].parse(reader, decoder, update));
if (pos_slot < 4)
return pos_slot;
const num_direct_bits = @as(u5, @intCast((pos_slot >> 1) - 1));
var result = (2 ^ (pos_slot & 1)) << num_direct_bits;
if (pos_slot < 14) {
result += try decoder.parseReverseBitTree(
reader,
num_direct_bits,
&self.pos_decoders,
result - pos_slot,
update,
);
} else {
result += @as(usize, try decoder.get(reader, num_direct_bits - 4)) << 4;
result += try self.align_decoder.parseReverse(reader, decoder, update);
}
return result;
}
};

View file

@ -1,228 +0,0 @@
const std = @import("../../../std.zig");
const math = std.math;
const mem = std.mem;
const Allocator = std.mem.Allocator;
const ArrayListUnmanaged = std.ArrayListUnmanaged;
/// An accumulating buffer for LZ sequences
pub const LzAccumBuffer = struct {
/// Buffer
buf: ArrayListUnmanaged(u8),
/// Buffer memory limit
memlimit: usize,
/// Total number of bytes sent through the buffer
len: usize,
const Self = @This();
pub fn init(memlimit: usize) Self {
return Self{
.buf = .{},
.memlimit = memlimit,
.len = 0,
};
}
pub fn appendByte(self: *Self, allocator: Allocator, byte: u8) !void {
try self.buf.append(allocator, byte);
self.len += 1;
}
/// Reset the internal dictionary
pub fn reset(self: *Self, writer: anytype) !void {
try writer.writeAll(self.buf.items);
self.buf.clearRetainingCapacity();
self.len = 0;
}
/// Retrieve the last byte or return a default
pub fn lastOr(self: Self, lit: u8) u8 {
const buf_len = self.buf.items.len;
return if (buf_len == 0)
lit
else
self.buf.items[buf_len - 1];
}
/// Retrieve the n-th last byte
pub fn lastN(self: Self, dist: usize) !u8 {
const buf_len = self.buf.items.len;
if (dist > buf_len) {
return error.CorruptInput;
}
return self.buf.items[buf_len - dist];
}
/// Append a literal
pub fn appendLiteral(
self: *Self,
allocator: Allocator,
lit: u8,
writer: anytype,
) !void {
_ = writer;
if (self.len >= self.memlimit) {
return error.CorruptInput;
}
try self.buf.append(allocator, lit);
self.len += 1;
}
/// Fetch an LZ sequence (length, distance) from inside the buffer
pub fn appendLz(
self: *Self,
allocator: Allocator,
len: usize,
dist: usize,
writer: anytype,
) !void {
_ = writer;
const buf_len = self.buf.items.len;
if (dist > buf_len) {
return error.CorruptInput;
}
var offset = buf_len - dist;
var i: usize = 0;
while (i < len) : (i += 1) {
const x = self.buf.items[offset];
try self.buf.append(allocator, x);
offset += 1;
}
self.len += len;
}
pub fn finish(self: *Self, writer: anytype) !void {
try writer.writeAll(self.buf.items);
self.buf.clearRetainingCapacity();
}
pub fn deinit(self: *Self, allocator: Allocator) void {
self.buf.deinit(allocator);
self.* = undefined;
}
};
/// A circular buffer for LZ sequences
pub const LzCircularBuffer = struct {
/// Circular buffer
buf: ArrayListUnmanaged(u8),
/// Length of the buffer
dict_size: usize,
/// Buffer memory limit
memlimit: usize,
/// Current position
cursor: usize,
/// Total number of bytes sent through the buffer
len: usize,
const Self = @This();
pub fn init(dict_size: usize, memlimit: usize) Self {
return Self{
.buf = .{},
.dict_size = dict_size,
.memlimit = memlimit,
.cursor = 0,
.len = 0,
};
}
pub fn get(self: Self, index: usize) u8 {
return if (0 <= index and index < self.buf.items.len)
self.buf.items[index]
else
0;
}
pub fn set(self: *Self, allocator: Allocator, index: usize, value: u8) !void {
if (index >= self.memlimit) {
return error.CorruptInput;
}
try self.buf.ensureTotalCapacity(allocator, index + 1);
while (self.buf.items.len < index) {
self.buf.appendAssumeCapacity(0);
}
self.buf.appendAssumeCapacity(value);
}
/// Retrieve the last byte or return a default
pub fn lastOr(self: Self, lit: u8) u8 {
return if (self.len == 0)
lit
else
self.get((self.dict_size + self.cursor - 1) % self.dict_size);
}
/// Retrieve the n-th last byte
pub fn lastN(self: Self, dist: usize) !u8 {
if (dist > self.dict_size or dist > self.len) {
return error.CorruptInput;
}
const offset = (self.dict_size + self.cursor - dist) % self.dict_size;
return self.get(offset);
}
/// Append a literal
pub fn appendLiteral(
self: *Self,
allocator: Allocator,
lit: u8,
writer: anytype,
) !void {
try self.set(allocator, self.cursor, lit);
self.cursor += 1;
self.len += 1;
// Flush the circular buffer to the output
if (self.cursor == self.dict_size) {
try writer.writeAll(self.buf.items);
self.cursor = 0;
}
}
/// Fetch an LZ sequence (length, distance) from inside the buffer
pub fn appendLz(
self: *Self,
allocator: Allocator,
len: usize,
dist: usize,
writer: anytype,
) !void {
if (dist > self.dict_size or dist > self.len) {
return error.CorruptInput;
}
var offset = (self.dict_size + self.cursor - dist) % self.dict_size;
var i: usize = 0;
while (i < len) : (i += 1) {
const x = self.get(offset);
try self.appendLiteral(allocator, x, writer);
offset += 1;
if (offset == self.dict_size) {
offset = 0;
}
}
}
pub fn finish(self: *Self, writer: anytype) !void {
if (self.cursor > 0) {
try writer.writeAll(self.buf.items[0..self.cursor]);
self.cursor = 0;
}
}
pub fn deinit(self: *Self, allocator: Allocator) void {
self.buf.deinit(allocator);
self.* = undefined;
}
};

View file

@ -1,181 +0,0 @@
const std = @import("../../../std.zig");
const mem = std.mem;
pub const RangeDecoder = struct {
range: u32,
code: u32,
pub fn init(reader: anytype) !RangeDecoder {
const reserved = try reader.readByte();
if (reserved != 0) {
return error.CorruptInput;
}
return RangeDecoder{
.range = 0xFFFF_FFFF,
.code = try reader.readInt(u32, .big),
};
}
pub fn fromParts(
range: u32,
code: u32,
) RangeDecoder {
return .{
.range = range,
.code = code,
};
}
pub fn set(self: *RangeDecoder, range: u32, code: u32) void {
self.range = range;
self.code = code;
}
pub inline fn isFinished(self: RangeDecoder) bool {
return self.code == 0;
}
inline fn normalize(self: *RangeDecoder, reader: anytype) !void {
if (self.range < 0x0100_0000) {
self.range <<= 8;
self.code = (self.code << 8) ^ @as(u32, try reader.readByte());
}
}
inline fn getBit(self: *RangeDecoder, reader: anytype) !bool {
self.range >>= 1;
const bit = self.code >= self.range;
if (bit)
self.code -= self.range;
try self.normalize(reader);
return bit;
}
pub fn get(self: *RangeDecoder, reader: anytype, count: usize) !u32 {
var result: u32 = 0;
var i: usize = 0;
while (i < count) : (i += 1)
result = (result << 1) ^ @intFromBool(try self.getBit(reader));
return result;
}
pub inline fn decodeBit(self: *RangeDecoder, reader: anytype, prob: *u16, update: bool) !bool {
const bound = (self.range >> 11) * prob.*;
if (self.code < bound) {
if (update)
prob.* += (0x800 - prob.*) >> 5;
self.range = bound;
try self.normalize(reader);
return false;
} else {
if (update)
prob.* -= prob.* >> 5;
self.code -= bound;
self.range -= bound;
try self.normalize(reader);
return true;
}
}
fn parseBitTree(
self: *RangeDecoder,
reader: anytype,
num_bits: u5,
probs: []u16,
update: bool,
) !u32 {
var tmp: u32 = 1;
var i: @TypeOf(num_bits) = 0;
while (i < num_bits) : (i += 1) {
const bit = try self.decodeBit(reader, &probs[tmp], update);
tmp = (tmp << 1) ^ @intFromBool(bit);
}
return tmp - (@as(u32, 1) << num_bits);
}
pub fn parseReverseBitTree(
self: *RangeDecoder,
reader: anytype,
num_bits: u5,
probs: []u16,
offset: usize,
update: bool,
) !u32 {
var result: u32 = 0;
var tmp: usize = 1;
var i: @TypeOf(num_bits) = 0;
while (i < num_bits) : (i += 1) {
const bit = @intFromBool(try self.decodeBit(reader, &probs[offset + tmp], update));
tmp = (tmp << 1) ^ bit;
result ^= @as(u32, bit) << i;
}
return result;
}
};
pub fn BitTree(comptime num_bits: usize) type {
return struct {
probs: [1 << num_bits]u16 = @splat(0x400),
const Self = @This();
pub fn parse(
self: *Self,
reader: anytype,
decoder: *RangeDecoder,
update: bool,
) !u32 {
return decoder.parseBitTree(reader, num_bits, &self.probs, update);
}
pub fn parseReverse(
self: *Self,
reader: anytype,
decoder: *RangeDecoder,
update: bool,
) !u32 {
return decoder.parseReverseBitTree(reader, num_bits, &self.probs, 0, update);
}
pub fn reset(self: *Self) void {
@memset(&self.probs, 0x400);
}
};
}
pub const LenDecoder = struct {
choice: u16 = 0x400,
choice2: u16 = 0x400,
low_coder: [16]BitTree(3) = @splat(.{}),
mid_coder: [16]BitTree(3) = @splat(.{}),
high_coder: BitTree(8) = .{},
pub fn decode(
self: *LenDecoder,
reader: anytype,
decoder: *RangeDecoder,
pos_state: usize,
update: bool,
) !usize {
if (!try decoder.decodeBit(reader, &self.choice, update)) {
return @as(usize, try self.low_coder[pos_state].parse(reader, decoder, update));
} else if (!try decoder.decodeBit(reader, &self.choice2, update)) {
return @as(usize, try self.mid_coder[pos_state].parse(reader, decoder, update)) + 8;
} else {
return @as(usize, try self.high_coder.parse(reader, decoder, update)) + 16;
}
}
pub fn reset(self: *LenDecoder) void {
self.choice = 0x400;
self.choice2 = 0x400;
for (&self.low_coder) |*t| t.reset();
for (&self.mid_coder) |*t| t.reset();
self.high_coder.reset();
}
};

View file

@ -1,24 +1,31 @@
const std = @import("../../std.zig");
const lzma = @import("../lzma.zig");
const lzma = std.compress.lzma;
fn testDecompress(compressed: []const u8) ![]u8 {
const allocator = std.testing.allocator;
var stream = std.io.fixedBufferStream(compressed);
var decompressor = try lzma.decompress(allocator, stream.reader());
const gpa = std.testing.allocator;
var stream: std.Io.Reader = .fixed(compressed);
var decompressor = try lzma.Decompress.initOptions(&stream, gpa, &.{}, .{}, std.math.maxInt(u32));
defer decompressor.deinit();
const reader = decompressor.reader();
return reader.readAllAlloc(allocator, std.math.maxInt(usize));
return decompressor.reader.allocRemaining(gpa, .unlimited);
}
fn testDecompressEqual(expected: []const u8, compressed: []const u8) !void {
const allocator = std.testing.allocator;
const gpa = std.testing.allocator;
const decomp = try testDecompress(compressed);
defer allocator.free(decomp);
defer gpa.free(decomp);
try std.testing.expectEqualSlices(u8, expected, decomp);
}
fn testDecompressError(expected: anyerror, compressed: []const u8) !void {
return std.testing.expectError(expected, testDecompress(compressed));
const gpa = std.testing.allocator;
var stream: std.Io.Reader = .fixed(compressed);
var decompressor = try lzma.Decompress.initOptions(&stream, gpa, &.{}, .{}, std.math.maxInt(u32));
defer decompressor.deinit();
try std.testing.expectError(error.ReadFailed, decompressor.reader.allocRemaining(gpa, .unlimited));
try std.testing.expectEqual(expected, decompressor.err orelse return error.TestFailed);
}
test "decompress empty world" {
@ -76,24 +83,26 @@ test "known size with end of payload marker" {
test "too big uncompressed size in header" {
try testDecompressError(
error.CorruptInput,
error.DecompressedSizeMismatch,
@embedFile("testdata/bad-too_big_size-with_eopm.lzma"),
);
}
test "too small uncompressed size in header" {
try testDecompressError(
error.CorruptInput,
error.DecompressedSizeMismatch,
@embedFile("testdata/bad-too_small_size-without_eopm-3.lzma"),
);
}
test "reading one byte" {
const gpa = std.testing.allocator;
const compressed = @embedFile("testdata/good-known_size-with_eopm.lzma");
var stream = std.io.fixedBufferStream(compressed);
var decompressor = try lzma.decompress(std.testing.allocator, stream.reader());
var stream: std.Io.Reader = .fixed(compressed);
var decompressor = try lzma.Decompress.initOptions(&stream, gpa, &.{}, .{}, std.math.maxInt(u32));
defer decompressor.deinit();
var buffer = [1]u8{0};
_ = try decompressor.read(buffer[0..]);
var buffer: [1]u8 = undefined;
try decompressor.reader.readSliceAll(&buffer);
try std.testing.expectEqual(72, buffer[0]);
}

View file

@ -1,128 +0,0 @@
const std = @import("../../std.zig");
const math = std.math;
const mem = std.mem;
const Allocator = std.mem.Allocator;
pub fn Vec2D(comptime T: type) type {
return struct {
data: []T,
cols: usize,
const Self = @This();
pub fn init(allocator: Allocator, value: T, size: struct { usize, usize }) !Self {
const len = try math.mul(usize, size[0], size[1]);
const data = try allocator.alloc(T, len);
@memset(data, value);
return Self{
.data = data,
.cols = size[1],
};
}
pub fn deinit(self: *Self, allocator: Allocator) void {
allocator.free(self.data);
self.* = undefined;
}
pub fn fill(self: *Self, value: T) void {
@memset(self.data, value);
}
inline fn _get(self: Self, row: usize) ![]T {
const start_row = try math.mul(usize, row, self.cols);
const end_row = try math.add(usize, start_row, self.cols);
return self.data[start_row..end_row];
}
pub fn get(self: Self, row: usize) ![]const T {
return self._get(row);
}
pub fn getMut(self: *Self, row: usize) ![]T {
return self._get(row);
}
};
}
const testing = std.testing;
const expectEqualSlices = std.testing.expectEqualSlices;
const expectError = std.testing.expectError;
test "init" {
const allocator = testing.allocator;
var vec2d = try Vec2D(i32).init(allocator, 1, .{ 2, 3 });
defer vec2d.deinit(allocator);
try expectEqualSlices(i32, &.{ 1, 1, 1 }, try vec2d.get(0));
try expectEqualSlices(i32, &.{ 1, 1, 1 }, try vec2d.get(1));
}
test "init overflow" {
const allocator = testing.allocator;
try expectError(
error.Overflow,
Vec2D(i32).init(allocator, 1, .{ math.maxInt(usize), math.maxInt(usize) }),
);
}
test "fill" {
const allocator = testing.allocator;
var vec2d = try Vec2D(i32).init(allocator, 0, .{ 2, 3 });
defer vec2d.deinit(allocator);
vec2d.fill(7);
try expectEqualSlices(i32, &.{ 7, 7, 7 }, try vec2d.get(0));
try expectEqualSlices(i32, &.{ 7, 7, 7 }, try vec2d.get(1));
}
test "get" {
var data = [_]i32{ 0, 1, 2, 3, 4, 5, 6, 7 };
const vec2d = Vec2D(i32){
.data = &data,
.cols = 2,
};
try expectEqualSlices(i32, &.{ 0, 1 }, try vec2d.get(0));
try expectEqualSlices(i32, &.{ 2, 3 }, try vec2d.get(1));
try expectEqualSlices(i32, &.{ 4, 5 }, try vec2d.get(2));
try expectEqualSlices(i32, &.{ 6, 7 }, try vec2d.get(3));
}
test "getMut" {
var data = [_]i32{ 0, 1, 2, 3, 4, 5, 6, 7 };
var vec2d = Vec2D(i32){
.data = &data,
.cols = 2,
};
const row = try vec2d.getMut(1);
row[1] = 9;
try expectEqualSlices(i32, &.{ 0, 1 }, try vec2d.get(0));
// (1, 1) should be 9.
try expectEqualSlices(i32, &.{ 2, 9 }, try vec2d.get(1));
try expectEqualSlices(i32, &.{ 4, 5 }, try vec2d.get(2));
try expectEqualSlices(i32, &.{ 6, 7 }, try vec2d.get(3));
}
test "get multiplication overflow" {
const allocator = testing.allocator;
var matrix = try Vec2D(i32).init(allocator, 0, .{ 3, 4 });
defer matrix.deinit(allocator);
const row = (math.maxInt(usize) / 4) + 1;
try expectError(error.Overflow, matrix.get(row));
try expectError(error.Overflow, matrix.getMut(row));
}
test "get addition overflow" {
const allocator = testing.allocator;
var matrix = try Vec2D(i32).init(allocator, 0, .{ 3, 5 });
defer matrix.deinit(allocator);
const row = math.maxInt(usize) / 5;
try expectError(error.Overflow, matrix.get(row));
try expectError(error.Overflow, matrix.getMut(row));
}

View file

@ -1,26 +1,282 @@
const std = @import("../std.zig");
const Allocator = std.mem.Allocator;
const ArrayList = std.ArrayList;
const lzma = std.compress.lzma;
const Writer = std.Io.Writer;
const Reader = std.Io.Reader;
pub const decode = @import("lzma2/decode.zig");
/// An accumulating buffer for LZ sequences
pub const AccumBuffer = struct {
/// Buffer
buf: ArrayList(u8),
/// Buffer memory limit
memlimit: usize,
/// Total number of bytes sent through the buffer
len: usize,
pub fn decompress(
allocator: Allocator,
reader: anytype,
writer: anytype,
) !void {
var decoder = try decode.Decoder.init(allocator);
defer decoder.deinit(allocator);
return decoder.decompress(allocator, reader, writer);
pub fn init(memlimit: usize) AccumBuffer {
return .{
.buf = .{},
.memlimit = memlimit,
.len = 0,
};
}
test {
pub fn appendByte(self: *AccumBuffer, allocator: Allocator, byte: u8) !void {
try self.buf.append(allocator, byte);
self.len += 1;
}
/// Reset the internal dictionary
pub fn reset(self: *AccumBuffer, writer: *Writer) !void {
try writer.writeAll(self.buf.items);
self.buf.clearRetainingCapacity();
self.len = 0;
}
/// Retrieve the last byte or return a default
pub fn lastOr(self: AccumBuffer, lit: u8) u8 {
const buf_len = self.buf.items.len;
return if (buf_len == 0)
lit
else
self.buf.items[buf_len - 1];
}
/// Retrieve the n-th last byte
pub fn lastN(self: AccumBuffer, dist: usize) !u8 {
const buf_len = self.buf.items.len;
if (dist > buf_len) {
return error.CorruptInput;
}
return self.buf.items[buf_len - dist];
}
/// Append a literal
pub fn appendLiteral(
self: *AccumBuffer,
allocator: Allocator,
lit: u8,
writer: *Writer,
) !void {
_ = writer;
if (self.len >= self.memlimit) {
return error.CorruptInput;
}
try self.buf.append(allocator, lit);
self.len += 1;
}
/// Fetch an LZ sequence (length, distance) from inside the buffer
pub fn appendLz(
self: *AccumBuffer,
allocator: Allocator,
len: usize,
dist: usize,
writer: *Writer,
) !void {
_ = writer;
const buf_len = self.buf.items.len;
if (dist > buf_len) {
return error.CorruptInput;
}
var offset = buf_len - dist;
var i: usize = 0;
while (i < len) : (i += 1) {
const x = self.buf.items[offset];
try self.buf.append(allocator, x);
offset += 1;
}
self.len += len;
}
pub fn finish(self: *AccumBuffer, writer: *Writer) !void {
try writer.writeAll(self.buf.items);
self.buf.clearRetainingCapacity();
}
pub fn deinit(self: *AccumBuffer, allocator: Allocator) void {
self.buf.deinit(allocator);
self.* = undefined;
}
};
pub const Decode = struct {
lzma_decode: lzma.Decode,
pub fn init(gpa: Allocator) !Decode {
return .{ .lzma_decode = try lzma.Decode.init(gpa, .{ .lc = 0, .lp = 0, .pb = 0 }) };
}
pub fn deinit(self: *Decode, gpa: Allocator) void {
self.lzma_decode.deinit(gpa);
self.* = undefined;
}
/// Returns how many compressed bytes were consumed.
pub fn decompress(d: *Decode, reader: *Reader, allocating: *Writer.Allocating) !u64 {
const gpa = allocating.allocator;
var accum = AccumBuffer.init(std.math.maxInt(usize));
defer accum.deinit(gpa);
var n_read: u64 = 0;
while (true) {
const status = try reader.takeByte();
n_read += 1;
switch (status) {
0 => break,
1 => n_read += try parseUncompressed(reader, allocating, &accum, true),
2 => n_read += try parseUncompressed(reader, allocating, &accum, false),
else => n_read += try d.parseLzma(reader, allocating, &accum, status),
}
}
try accum.finish(&allocating.writer);
return n_read;
}
fn parseLzma(
d: *Decode,
reader: *Reader,
allocating: *Writer.Allocating,
accum: *AccumBuffer,
status: u8,
) !u64 {
if (status & 0x80 == 0) return error.CorruptInput;
const Reset = struct {
dict: bool,
state: bool,
props: bool,
};
const reset: Reset = switch ((status >> 5) & 0x3) {
0 => .{
.dict = false,
.state = false,
.props = false,
},
1 => .{
.dict = false,
.state = true,
.props = false,
},
2 => .{
.dict = false,
.state = true,
.props = true,
},
3 => .{
.dict = true,
.state = true,
.props = true,
},
else => unreachable,
};
var n_read: u64 = 0;
const unpacked_size = blk: {
var tmp: u64 = status & 0x1F;
tmp <<= 16;
tmp |= try reader.takeInt(u16, .big);
n_read += 2;
break :blk tmp + 1;
};
const packed_size = blk: {
const tmp: u17 = try reader.takeInt(u16, .big);
n_read += 2;
break :blk tmp + 1;
};
if (reset.dict) try accum.reset(&allocating.writer);
const ld = &d.lzma_decode;
if (reset.state) {
var new_props = ld.properties;
if (reset.props) {
var props = try reader.takeByte();
n_read += 1;
if (props >= 225) {
return error.CorruptInput;
}
const lc = @as(u4, @intCast(props % 9));
props /= 9;
const lp = @as(u3, @intCast(props % 5));
props /= 5;
const pb = @as(u3, @intCast(props));
if (lc + lp > 4) {
return error.CorruptInput;
}
new_props = .{ .lc = lc, .lp = lp, .pb = pb };
}
try ld.resetState(allocating.allocator, new_props);
}
const expected_unpacked_size = accum.len + unpacked_size;
const start_count = n_read;
var range_decoder = try lzma.RangeDecoder.initCounting(reader, &n_read);
while (true) {
if (accum.len >= expected_unpacked_size) break;
if (range_decoder.isFinished()) break;
switch (try ld.process(reader, allocating, accum, &range_decoder, &n_read)) {
.more => continue,
.finished => break,
}
}
if (accum.len != expected_unpacked_size) return error.DecompressedSizeMismatch;
if (n_read - start_count != packed_size) return error.CompressedSizeMismatch;
return n_read;
}
fn parseUncompressed(
reader: *Reader,
allocating: *Writer.Allocating,
accum: *AccumBuffer,
reset_dict: bool,
) !usize {
const unpacked_size = @as(u17, try reader.takeInt(u16, .big)) + 1;
if (reset_dict) try accum.reset(&allocating.writer);
const gpa = allocating.allocator;
for (0..unpacked_size) |_| {
try accum.appendByte(gpa, try reader.takeByte());
}
return 2 + unpacked_size;
}
};
test "decompress hello world stream" {
const expected = "Hello\nWorld!\n";
const compressed = &[_]u8{ 0x01, 0x00, 0x05, 0x48, 0x65, 0x6C, 0x6C, 0x6F, 0x0A, 0x02, 0x00, 0x06, 0x57, 0x6F, 0x72, 0x6C, 0x64, 0x21, 0x0A, 0x00 };
const allocator = std.testing.allocator;
var decomp = std.array_list.Managed(u8).init(allocator);
defer decomp.deinit();
var stream = std.io.fixedBufferStream(compressed);
try decompress(allocator, stream.reader(), decomp.writer());
try std.testing.expectEqualSlices(u8, expected, decomp.items);
const gpa = std.testing.allocator;
var decode = try Decode.init(gpa);
defer decode.deinit(gpa);
var stream: std.Io.Reader = .fixed(compressed);
var result: std.Io.Writer.Allocating = .init(gpa);
defer result.deinit();
const n_read = try decode.decompress(&stream, &result);
try std.testing.expectEqual(compressed.len, n_read);
try std.testing.expectEqualStrings(expected, result.written());
}

View file

@ -1,169 +0,0 @@
const std = @import("../../std.zig");
const Allocator = std.mem.Allocator;
const lzma = @import("../lzma.zig");
const DecoderState = lzma.decode.DecoderState;
const LzAccumBuffer = lzma.decode.lzbuffer.LzAccumBuffer;
const Properties = lzma.decode.Properties;
const RangeDecoder = lzma.decode.rangecoder.RangeDecoder;
pub const Decoder = struct {
lzma_state: DecoderState,
pub fn init(allocator: Allocator) !Decoder {
return Decoder{
.lzma_state = try DecoderState.init(
allocator,
Properties{
.lc = 0,
.lp = 0,
.pb = 0,
},
null,
),
};
}
pub fn deinit(self: *Decoder, allocator: Allocator) void {
self.lzma_state.deinit(allocator);
self.* = undefined;
}
pub fn decompress(
self: *Decoder,
allocator: Allocator,
reader: anytype,
writer: anytype,
) !void {
var accum = LzAccumBuffer.init(std.math.maxInt(usize));
defer accum.deinit(allocator);
while (true) {
const status = try reader.readByte();
switch (status) {
0 => break,
1 => try parseUncompressed(allocator, reader, writer, &accum, true),
2 => try parseUncompressed(allocator, reader, writer, &accum, false),
else => try self.parseLzma(allocator, reader, writer, &accum, status),
}
}
try accum.finish(writer);
}
fn parseLzma(
self: *Decoder,
allocator: Allocator,
reader: anytype,
writer: anytype,
accum: *LzAccumBuffer,
status: u8,
) !void {
if (status & 0x80 == 0) {
return error.CorruptInput;
}
const Reset = struct {
dict: bool,
state: bool,
props: bool,
};
const reset = switch ((status >> 5) & 0x3) {
0 => Reset{
.dict = false,
.state = false,
.props = false,
},
1 => Reset{
.dict = false,
.state = true,
.props = false,
},
2 => Reset{
.dict = false,
.state = true,
.props = true,
},
3 => Reset{
.dict = true,
.state = true,
.props = true,
},
else => unreachable,
};
const unpacked_size = blk: {
var tmp: u64 = status & 0x1F;
tmp <<= 16;
tmp |= try reader.readInt(u16, .big);
break :blk tmp + 1;
};
const packed_size = blk: {
const tmp: u17 = try reader.readInt(u16, .big);
break :blk tmp + 1;
};
if (reset.dict) {
try accum.reset(writer);
}
if (reset.state) {
var new_props = self.lzma_state.lzma_props;
if (reset.props) {
var props = try reader.readByte();
if (props >= 225) {
return error.CorruptInput;
}
const lc = @as(u4, @intCast(props % 9));
props /= 9;
const lp = @as(u3, @intCast(props % 5));
props /= 5;
const pb = @as(u3, @intCast(props));
if (lc + lp > 4) {
return error.CorruptInput;
}
new_props = Properties{ .lc = lc, .lp = lp, .pb = pb };
}
try self.lzma_state.resetState(allocator, new_props);
}
self.lzma_state.unpacked_size = unpacked_size + accum.len;
var counter = std.io.countingReader(reader);
const counter_reader = counter.reader();
var rangecoder = try RangeDecoder.init(counter_reader);
while (try self.lzma_state.process(allocator, counter_reader, writer, accum, &rangecoder) == .continue_) {}
if (counter.bytes_read != packed_size) {
return error.CorruptInput;
}
}
fn parseUncompressed(
allocator: Allocator,
reader: anytype,
writer: anytype,
accum: *LzAccumBuffer,
reset_dict: bool,
) !void {
const unpacked_size = @as(u17, try reader.readInt(u16, .big)) + 1;
if (reset_dict) {
try accum.reset(writer);
}
var i: @TypeOf(unpacked_size) = 0;
while (i < unpacked_size) : (i += 1) {
try accum.appendByte(allocator, try reader.readByte());
}
}
};

View file

@ -1,165 +1,4 @@
const std = @import("std");
const block = @import("xz/block.zig");
const Allocator = std.mem.Allocator;
const Crc32 = std.hash.Crc32;
pub const Check = enum(u4) {
none = 0x00,
crc32 = 0x01,
crc64 = 0x04,
sha256 = 0x0A,
_,
};
fn readStreamFlags(reader: anytype, check: *Check) !void {
const reserved1 = try reader.readByte();
if (reserved1 != 0) return error.CorruptInput;
const byte = try reader.readByte();
if ((byte >> 4) != 0) return error.CorruptInput;
check.* = @enumFromInt(@as(u4, @truncate(byte)));
}
pub fn decompress(allocator: Allocator, reader: anytype) !Decompress(@TypeOf(reader)) {
return Decompress(@TypeOf(reader)).init(allocator, reader);
}
pub fn Decompress(comptime ReaderType: type) type {
return struct {
const Self = @This();
pub const Error = ReaderType.Error || block.Decoder(ReaderType).Error;
pub const Reader = std.io.GenericReader(*Self, Error, read);
allocator: Allocator,
block_decoder: block.Decoder(ReaderType),
in_reader: ReaderType,
fn init(allocator: Allocator, source: ReaderType) !Self {
const magic = try source.readBytesNoEof(6);
if (!std.mem.eql(u8, &magic, &.{ 0xFD, '7', 'z', 'X', 'Z', 0x00 }))
return error.BadHeader;
var check: Check = undefined;
const hash_a = blk: {
var hasher = hashedReader(source, Crc32.init());
try readStreamFlags(hasher.reader(), &check);
break :blk hasher.hasher.final();
};
const hash_b = try source.readInt(u32, .little);
if (hash_a != hash_b)
return error.WrongChecksum;
return Self{
.allocator = allocator,
.block_decoder = try block.decoder(allocator, source, check),
.in_reader = source,
};
}
pub fn deinit(self: *Self) void {
self.block_decoder.deinit();
}
pub fn reader(self: *Self) Reader {
return .{ .context = self };
}
pub fn read(self: *Self, buffer: []u8) Error!usize {
if (buffer.len == 0)
return 0;
const r = try self.block_decoder.read(buffer);
if (r != 0)
return r;
const index_size = blk: {
var hasher = hashedReader(self.in_reader, Crc32.init());
hasher.hasher.update(&[1]u8{0x00});
var counter = std.io.countingReader(hasher.reader());
counter.bytes_read += 1;
const counting_reader = counter.reader();
const record_count = try std.leb.readUleb128(u64, counting_reader);
if (record_count != self.block_decoder.block_count)
return error.CorruptInput;
var i: usize = 0;
while (i < record_count) : (i += 1) {
// TODO: validate records
_ = try std.leb.readUleb128(u64, counting_reader);
_ = try std.leb.readUleb128(u64, counting_reader);
}
while (counter.bytes_read % 4 != 0) {
if (try counting_reader.readByte() != 0)
return error.CorruptInput;
}
const hash_a = hasher.hasher.final();
const hash_b = try counting_reader.readInt(u32, .little);
if (hash_a != hash_b)
return error.WrongChecksum;
break :blk counter.bytes_read;
};
const hash_a = try self.in_reader.readInt(u32, .little);
const hash_b = blk: {
var hasher = hashedReader(self.in_reader, Crc32.init());
const hashed_reader = hasher.reader();
const backward_size = (@as(u64, try hashed_reader.readInt(u32, .little)) + 1) * 4;
if (backward_size != index_size)
return error.CorruptInput;
var check: Check = undefined;
try readStreamFlags(hashed_reader, &check);
break :blk hasher.hasher.final();
};
if (hash_a != hash_b)
return error.WrongChecksum;
const magic = try self.in_reader.readBytesNoEof(2);
if (!std.mem.eql(u8, &magic, &.{ 'Y', 'Z' }))
return error.CorruptInput;
return 0;
}
};
}
pub fn HashedReader(ReaderType: type, HasherType: type) type {
return struct {
child_reader: ReaderType,
hasher: HasherType,
pub const Error = ReaderType.Error;
pub const Reader = std.io.GenericReader(*@This(), Error, read);
pub fn read(self: *@This(), buf: []u8) Error!usize {
const amt = try self.child_reader.read(buf);
self.hasher.update(buf[0..amt]);
return amt;
}
pub fn reader(self: *@This()) Reader {
return .{ .context = self };
}
};
}
pub fn hashedReader(
reader: anytype,
hasher: anytype,
) HashedReader(@TypeOf(reader), @TypeOf(hasher)) {
return .{ .child_reader = reader, .hasher = hasher };
}
pub const Decompress = @import("xz/Decompress.zig");
test {
_ = @import("xz/test.zig");

View file

@ -0,0 +1,319 @@
const Decompress = @This();
const std = @import("../../std.zig");
const Allocator = std.mem.Allocator;
const ArrayList = std.ArrayList;
const Crc32 = std.hash.Crc32;
const Crc64 = std.hash.crc.Crc64Xz;
const Sha256 = std.crypto.hash.sha2.Sha256;
const lzma2 = std.compress.lzma2;
const Writer = std.Io.Writer;
const Reader = std.Io.Reader;
const assert = std.debug.assert;
/// Underlying compressed data stream to pull bytes from.
input: *Reader,
/// Uncompressed bytes output by this stream implementation.
reader: Reader,
gpa: Allocator,
check: Check,
block_count: usize,
err: ?Error,
pub const Error = error{
ReadFailed,
OutOfMemory,
CorruptInput,
EndOfStream,
WrongChecksum,
Unsupported,
Overflow,
InvalidRangeCode,
DecompressedSizeMismatch,
CompressedSizeMismatch,
};
pub const Check = enum(u4) {
none = 0x00,
crc32 = 0x01,
crc64 = 0x04,
sha256 = 0x0A,
_,
};
pub const StreamFlags = packed struct(u16) {
null: u8 = 0,
check: Check,
reserved: u4 = 0,
};
pub const InitError = error{
NotXzStream,
WrongChecksum,
};
/// XZ uses a series of LZMA2 blocks which each specify a dictionary size
/// anywhere from 4K to 4G. Thus, this API dynamically allocates the dictionary
/// as-needed.
pub fn init(
input: *Reader,
gpa: Allocator,
/// Decompress takes ownership of this buffer and resizes it with `gpa`.
buffer: []u8,
) !Decompress {
const magic = try input.takeArray(6);
if (!std.mem.eql(u8, magic, &.{ 0xFD, '7', 'z', 'X', 'Z', 0x00 }))
return error.NotXzStream;
const computed_checksum = Crc32.hash(try input.peek(@sizeOf(StreamFlags)));
const stream_flags = input.takeStruct(StreamFlags, .little) catch unreachable;
const stored_hash = try input.takeInt(u32, .little);
if (computed_checksum != stored_hash) return error.WrongChecksum;
return .{
.input = input,
.reader = .{
.vtable = &.{
.stream = stream,
.readVec = readVec,
.discard = discard,
},
.buffer = buffer,
.seek = 0,
.end = 0,
},
.gpa = gpa,
.check = stream_flags.check,
.block_count = 0,
.err = null,
};
}
/// Reclaim ownership of the buffer passed to `init`.
pub fn takeBuffer(d: *Decompress) []u8 {
const buffer = d.reader.buffer;
d.reader.buffer = &.{};
return buffer;
}
pub fn deinit(d: *Decompress) void {
const gpa = d.gpa;
gpa.free(d.reader.buffer);
d.* = undefined;
}
fn readVec(r: *Reader, data: [][]u8) Reader.Error!usize {
_ = data;
return readIndirect(r);
}
fn stream(r: *Reader, w: *Writer, limit: std.Io.Limit) Reader.StreamError!usize {
_ = w;
_ = limit;
return readIndirect(r);
}
fn discard(r: *Reader, limit: std.Io.Limit) Reader.Error!usize {
const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
_ = d;
_ = limit;
@panic("TODO");
}
fn readIndirect(r: *Reader) Reader.Error!usize {
const d: *Decompress = @alignCast(@fieldParentPtr("reader", r));
const gpa = d.gpa;
const input = d.input;
var allocating = Writer.Allocating.initOwnedSlice(gpa, r.buffer);
allocating.writer.end = r.end;
defer {
r.buffer = allocating.writer.buffer;
r.end = allocating.writer.end;
}
if (d.err != null) return error.ReadFailed;
if (d.block_count == std.math.maxInt(usize)) return error.EndOfStream;
readBlock(input, &allocating) catch |err| switch (err) {
error.WriteFailed => {
d.err = error.OutOfMemory;
return error.ReadFailed;
},
error.SuccessfulEndOfStream => {
finish(d) catch |finish_err| {
d.err = finish_err;
return error.ReadFailed;
};
d.block_count = std.math.maxInt(usize);
return error.EndOfStream;
},
else => |e| {
d.err = e;
return error.ReadFailed;
},
};
switch (d.check) {
.none => {},
.crc32 => {
const declared_checksum = try input.takeInt(u32, .little);
// TODO
//const hash_a = Crc32.hash(unpacked_bytes);
//if (hash_a != hash_b) return error.WrongChecksum;
_ = declared_checksum;
},
.crc64 => {
const declared_checksum = try input.takeInt(u64, .little);
// TODO
//const hash_a = Crc64.hash(unpacked_bytes);
//if (hash_a != hash_b) return error.WrongChecksum;
_ = declared_checksum;
},
.sha256 => {
const declared_hash = try input.take(Sha256.digest_length);
// TODO
//var hash_a: [Sha256.digest_length]u8 = undefined;
//Sha256.hash(unpacked_bytes, &hash_a, .{});
//if (!std.mem.eql(u8, &hash_a, &hash_b))
// return error.WrongChecksum;
_ = declared_hash;
},
else => {
d.err = error.Unsupported;
return error.ReadFailed;
},
}
d.block_count += 1;
return 0;
}
fn readBlock(input: *Reader, allocating: *Writer.Allocating) !void {
var packed_size: ?u64 = null;
var unpacked_size: ?u64 = null;
const header_size = h: {
// Read the block header via peeking so that we can hash the whole thing too.
const first_byte: usize = try input.peekByte();
if (first_byte == 0) return error.SuccessfulEndOfStream;
const declared_header_size = first_byte * 4;
try input.fill(declared_header_size);
const header_seek_start = input.seek;
input.toss(1);
const Flags = packed struct(u8) {
last_filter_index: u2,
reserved: u4,
has_packed_size: bool,
has_unpacked_size: bool,
};
const flags = try input.takeStruct(Flags, .little);
const filter_count = @as(u3, flags.last_filter_index) + 1;
if (filter_count > 1) return error.Unsupported;
if (flags.has_packed_size) packed_size = try input.takeLeb128(u64);
if (flags.has_unpacked_size) unpacked_size = try input.takeLeb128(u64);
const FilterId = enum(u64) {
lzma2 = 0x21,
_,
};
const filter_id: FilterId = @enumFromInt(try input.takeLeb128(u64));
if (filter_id != .lzma2) return error.Unsupported;
const properties_size = try input.takeLeb128(u64);
if (properties_size != 1) return error.CorruptInput;
// TODO: use filter properties
_ = try input.takeByte();
const actual_header_size = input.seek - header_seek_start;
if (actual_header_size > declared_header_size) return error.CorruptInput;
const remaining_bytes = declared_header_size - actual_header_size;
for (0..remaining_bytes) |_| {
if (try input.takeByte() != 0) return error.CorruptInput;
}
const header_slice = input.buffer[header_seek_start..][0..declared_header_size];
const computed_checksum = Crc32.hash(header_slice);
const declared_checksum = try input.takeInt(u32, .little);
if (computed_checksum != declared_checksum) return error.WrongChecksum;
break :h declared_header_size;
};
// Compressed Data
var lzma2_decode = try lzma2.Decode.init(allocating.allocator);
defer lzma2_decode.deinit(allocating.allocator);
const before_size = allocating.writer.end;
const packed_bytes_read = try lzma2_decode.decompress(input, allocating);
const unpacked_bytes = allocating.writer.end - before_size;
if (packed_size) |s| {
if (s != packed_bytes_read) return error.CorruptInput;
}
if (unpacked_size) |s| {
if (s != unpacked_bytes) return error.CorruptInput;
}
// Block Padding
const block_counter = header_size + packed_bytes_read;
const padding = try input.take(@intCast((4 - (block_counter % 4)) % 4));
for (padding) |byte| {
if (byte != 0) return error.CorruptInput;
}
}
fn finish(d: *Decompress) !void {
const input = d.input;
const index_size = blk: {
// Assume that we already peeked a zero in readBlock().
assert(input.buffered()[0] == 0);
var input_counter: u64 = 1;
var checksum: Crc32 = .init();
checksum.update(&.{0});
input.toss(1);
const record_count = try countLeb128(input, u64, &input_counter, &checksum);
if (record_count != d.block_count)
return error.CorruptInput;
for (0..@intCast(record_count)) |_| {
// TODO: validate records
_ = try countLeb128(input, u64, &input_counter, &checksum);
_ = try countLeb128(input, u64, &input_counter, &checksum);
}
const padding = try input.take(@intCast((4 - (input_counter % 4)) % 4));
for (padding) |byte| {
if (byte != 0) return error.CorruptInput;
}
checksum.update(padding);
const declared_checksum = try input.takeInt(u32, .little);
const computed_checksum = checksum.final();
if (computed_checksum != declared_checksum) return error.WrongChecksum;
break :blk input_counter + padding.len + 4;
};
const declared_checksum = try input.takeInt(u32, .little);
const computed_checksum = Crc32.hash(try input.peek(4 + @sizeOf(StreamFlags)));
if (declared_checksum != computed_checksum) return error.WrongChecksum;
const backward_size = (@as(u64, try input.takeInt(u32, .little)) + 1) * 4;
if (backward_size != index_size) return error.CorruptInput;
input.toss(@sizeOf(StreamFlags));
if (!std.mem.eql(u8, try input.takeArray(2), &.{ 'Y', 'Z' }))
return error.CorruptInput;
}
fn countLeb128(reader: *Reader, comptime T: type, counter: *u64, hasher: *Crc32) !T {
try reader.fill(8);
const start = reader.seek;
const result = try reader.takeLeb128(T);
const read_slice = reader.buffer[start..reader.seek];
hasher.update(read_slice);
counter.* += read_slice.len;
return result;
}

View file

@ -1,208 +0,0 @@
const std = @import("../../std.zig");
const lzma2 = std.compress.lzma2;
const Allocator = std.mem.Allocator;
const ArrayListUnmanaged = std.ArrayListUnmanaged;
const Crc32 = std.hash.Crc32;
const Crc64 = std.hash.crc.Crc64Xz;
const Sha256 = std.crypto.hash.sha2.Sha256;
const xz = std.compress.xz;
const DecodeError = error{
CorruptInput,
EndOfStream,
EndOfStreamWithNoError,
WrongChecksum,
Unsupported,
Overflow,
};
pub fn decoder(allocator: Allocator, reader: anytype, check: xz.Check) !Decoder(@TypeOf(reader)) {
return Decoder(@TypeOf(reader)).init(allocator, reader, check);
}
pub fn Decoder(comptime ReaderType: type) type {
return struct {
const Self = @This();
pub const Error =
ReaderType.Error ||
DecodeError ||
Allocator.Error;
pub const Reader = std.io.GenericReader(*Self, Error, read);
allocator: Allocator,
inner_reader: ReaderType,
check: xz.Check,
err: ?Error,
to_read: ArrayListUnmanaged(u8),
read_pos: usize,
block_count: usize,
fn init(allocator: Allocator, in_reader: ReaderType, check: xz.Check) !Self {
return Self{
.allocator = allocator,
.inner_reader = in_reader,
.check = check,
.err = null,
.to_read = .{},
.read_pos = 0,
.block_count = 0,
};
}
pub fn deinit(self: *Self) void {
self.to_read.deinit(self.allocator);
}
pub fn reader(self: *Self) Reader {
return .{ .context = self };
}
pub fn read(self: *Self, output: []u8) Error!usize {
while (true) {
const unread_len = self.to_read.items.len - self.read_pos;
if (unread_len > 0) {
const n = @min(unread_len, output.len);
@memcpy(output[0..n], self.to_read.items[self.read_pos..][0..n]);
self.read_pos += n;
return n;
}
if (self.err) |e| {
if (e == DecodeError.EndOfStreamWithNoError) {
return 0;
}
return e;
}
if (self.read_pos > 0) {
self.to_read.shrinkRetainingCapacity(0);
self.read_pos = 0;
}
self.readBlock() catch |e| {
self.err = e;
};
}
}
fn readBlock(self: *Self) Error!void {
var block_counter = std.io.countingReader(self.inner_reader);
const block_reader = block_counter.reader();
var packed_size: ?u64 = null;
var unpacked_size: ?u64 = null;
// Block Header
{
var header_hasher = xz.hashedReader(block_reader, Crc32.init());
const header_reader = header_hasher.reader();
const header_size = @as(u64, try header_reader.readByte()) * 4;
if (header_size == 0)
return error.EndOfStreamWithNoError;
const Flags = packed struct(u8) {
last_filter_index: u2,
reserved: u4,
has_packed_size: bool,
has_unpacked_size: bool,
};
const flags = @as(Flags, @bitCast(try header_reader.readByte()));
const filter_count = @as(u3, flags.last_filter_index) + 1;
if (filter_count > 1)
return error.Unsupported;
if (flags.has_packed_size)
packed_size = try std.leb.readUleb128(u64, header_reader);
if (flags.has_unpacked_size)
unpacked_size = try std.leb.readUleb128(u64, header_reader);
const FilterId = enum(u64) {
lzma2 = 0x21,
_,
};
const filter_id = @as(
FilterId,
@enumFromInt(try std.leb.readUleb128(u64, header_reader)),
);
if (@intFromEnum(filter_id) >= 0x4000_0000_0000_0000)
return error.CorruptInput;
if (filter_id != .lzma2)
return error.Unsupported;
const properties_size = try std.leb.readUleb128(u64, header_reader);
if (properties_size != 1)
return error.CorruptInput;
// TODO: use filter properties
_ = try header_reader.readByte();
while (block_counter.bytes_read != header_size) {
if (try header_reader.readByte() != 0)
return error.CorruptInput;
}
const hash_a = header_hasher.hasher.final();
const hash_b = try header_reader.readInt(u32, .little);
if (hash_a != hash_b)
return error.WrongChecksum;
}
// Compressed Data
var packed_counter = std.io.countingReader(block_reader);
try lzma2.decompress(
self.allocator,
packed_counter.reader(),
self.to_read.writer(self.allocator),
);
if (packed_size) |s| {
if (s != packed_counter.bytes_read)
return error.CorruptInput;
}
const unpacked_bytes = self.to_read.items;
if (unpacked_size) |s| {
if (s != unpacked_bytes.len)
return error.CorruptInput;
}
// Block Padding
while (block_counter.bytes_read % 4 != 0) {
if (try block_reader.readByte() != 0)
return error.CorruptInput;
}
switch (self.check) {
.none => {},
.crc32 => {
const hash_a = Crc32.hash(unpacked_bytes);
const hash_b = try self.inner_reader.readInt(u32, .little);
if (hash_a != hash_b)
return error.WrongChecksum;
},
.crc64 => {
const hash_a = Crc64.hash(unpacked_bytes);
const hash_b = try self.inner_reader.readInt(u64, .little);
if (hash_a != hash_b)
return error.WrongChecksum;
},
.sha256 => {
var hash_a: [Sha256.digest_length]u8 = undefined;
Sha256.hash(unpacked_bytes, &hash_a, .{});
var hash_b: [Sha256.digest_length]u8 = undefined;
try self.inner_reader.readNoEof(&hash_b);
if (!std.mem.eql(u8, &hash_a, &hash_b))
return error.WrongChecksum;
},
else => return error.Unsupported,
}
self.block_count += 1;
}
};
}

View file

@ -3,48 +3,79 @@ const testing = std.testing;
const xz = std.compress.xz;
fn decompress(data: []const u8) ![]u8 {
var in_stream = std.io.fixedBufferStream(data);
const gpa = testing.allocator;
var xz_stream = try xz.decompress(testing.allocator, in_stream.reader());
var in_stream: std.Io.Reader = .fixed(data);
var xz_stream = try xz.Decompress.init(&in_stream, gpa, &.{});
defer xz_stream.deinit();
return xz_stream.reader().readAllAlloc(testing.allocator, std.math.maxInt(usize));
return xz_stream.reader.allocRemaining(gpa, .unlimited);
}
fn testReader(data: []const u8, comptime expected: []const u8) !void {
const buf = try decompress(data);
defer testing.allocator.free(buf);
fn testReader(data: []const u8, expected: []const u8) !void {
const gpa = testing.allocator;
try testing.expectEqualSlices(u8, expected, buf);
const result = try decompress(data);
defer gpa.free(result);
try testing.expectEqualSlices(u8, expected, result);
}
test "compressed data" {
fn testDecompressError(expected: anyerror, compressed: []const u8) !void {
const gpa = std.testing.allocator;
var stream: std.Io.Reader = .fixed(compressed);
var decompressor = try xz.Decompress.init(&stream, gpa, &.{});
defer decompressor.deinit();
try std.testing.expectError(error.ReadFailed, decompressor.reader.allocRemaining(gpa, .unlimited));
try std.testing.expectEqual(expected, decompressor.err orelse return error.TestFailed);
}
test "fixture good-0-empty.xz" {
try testReader(@embedFile("testdata/good-0-empty.xz"), "");
}
inline for ([_][]const u8{
"good-1-check-none.xz",
"good-1-check-crc32.xz",
"good-1-check-crc64.xz",
"good-1-check-sha256.xz",
"good-2-lzma2.xz",
"good-1-block_header-1.xz",
"good-1-block_header-2.xz",
"good-1-block_header-3.xz",
}) |filename| {
try testReader(@embedFile("testdata/" ++ filename),
const hello_world_text =
\\Hello
\\World!
\\
);
;
test "fixture good-1-check-none.xz" {
try testReader(@embedFile("testdata/good-1-check-none.xz"), hello_world_text);
}
inline for ([_][]const u8{
"good-1-lzma2-1.xz",
"good-1-lzma2-2.xz",
"good-1-lzma2-3.xz",
"good-1-lzma2-4.xz",
}) |filename| {
try testReader(@embedFile("testdata/" ++ filename),
test "fixture good-1-check-crc32.xz" {
try testReader(@embedFile("testdata/good-1-check-crc32.xz"), hello_world_text);
}
test "fixture good-1-check-crc64.xz" {
try testReader(@embedFile("testdata/good-1-check-crc64.xz"), hello_world_text);
}
test "fixture good-1-check-sha256.xz" {
try testReader(@embedFile("testdata/good-1-check-sha256.xz"), hello_world_text);
}
test "fixture good-2-lzma2.xz" {
try testReader(@embedFile("testdata/good-2-lzma2.xz"), hello_world_text);
}
test "fixture good-1-block_header-1.xz" {
try testReader(@embedFile("testdata/good-1-block_header-1.xz"), hello_world_text);
}
test "fixture good-1-block_header-2.xz" {
try testReader(@embedFile("testdata/good-1-block_header-2.xz"), hello_world_text);
}
test "fixture good-1-block_header-3.xz" {
try testReader(@embedFile("testdata/good-1-block_header-3.xz"), hello_world_text);
}
const lorem_ipsum_text =
\\Lorem ipsum dolor sit amet, consectetur adipisicing
\\elit, sed do eiusmod tempor incididunt ut
\\labore et dolore magna aliqua. Ut enim
@ -56,27 +87,54 @@ test "compressed data" {
\\non proident, sunt in culpa qui officia
\\deserunt mollit anim id est laborum.
\\
);
;
test "fixture good-1-lzma2-1.xz" {
try testReader(@embedFile("testdata/good-1-lzma2-1.xz"), lorem_ipsum_text);
}
test "fixture good-1-lzma2-2.xz" {
try testReader(@embedFile("testdata/good-1-lzma2-2.xz"), lorem_ipsum_text);
}
test "fixture good-1-lzma2-3.xz" {
try testReader(@embedFile("testdata/good-1-lzma2-3.xz"), lorem_ipsum_text);
}
test "fixture good-1-lzma2-4.xz" {
try testReader(@embedFile("testdata/good-1-lzma2-4.xz"), lorem_ipsum_text);
}
test "fixture good-1-lzma2-5.xz" {
try testReader(@embedFile("testdata/good-1-lzma2-5.xz"), "");
}
test "unsupported" {
inline for ([_][]const u8{
"good-1-delta-lzma2.tiff.xz",
"good-1-x86-lzma2.xz",
"good-1-sparc-lzma2.xz",
"good-1-arm64-lzma2-1.xz",
"good-1-arm64-lzma2-2.xz",
"good-1-3delta-lzma2.xz",
"good-1-empty-bcj-lzma2.xz",
}) |filename| {
try testing.expectError(
error.Unsupported,
decompress(@embedFile("testdata/" ++ filename)),
);
test "fixture good-1-delta-lzma2.tiff.xz" {
try testDecompressError(error.Unsupported, @embedFile("testdata/good-1-delta-lzma2.tiff.xz"));
}
test "fixture good-1-x86-lzma2.xz" {
try testDecompressError(error.Unsupported, @embedFile("testdata/good-1-x86-lzma2.xz"));
}
test "fixture good-1-sparc-lzma2.xz" {
try testDecompressError(error.Unsupported, @embedFile("testdata/good-1-sparc-lzma2.xz"));
}
test "fixture good-1-arm64-lzma2-1.xz" {
try testDecompressError(error.Unsupported, @embedFile("testdata/good-1-arm64-lzma2-1.xz"));
}
test "fixture good-1-arm64-lzma2-2.xz" {
try testDecompressError(error.Unsupported, @embedFile("testdata/good-1-arm64-lzma2-2.xz"));
}
test "fixture good-1-3delta-lzma2.xz" {
try testDecompressError(error.Unsupported, @embedFile("testdata/good-1-3delta-lzma2.xz"));
}
test "fixture good-1-empty-bcj-lzma2.xz" {
try testDecompressError(error.Unsupported, @embedFile("testdata/good-1-empty-bcj-lzma2.xz"));
}
fn testDontPanic(data: []const u8) !void {
@ -91,6 +149,8 @@ test "size fields: integer overflow avoidance" {
// These cases were found via fuzz testing and each previously caused
// an integer overflow when decoding. We just want to ensure they no longer
// cause a panic
// TODO this not a sufficient way to test. tests should always check the result,
// not merely ensure that the code does not crash.
const header_size_overflow = "\xfd7zXZ\x00\x00\x01i\"\xde6z";
try testDontPanic(header_size_overflow);
const lzma2_chunk_size_overflow = "\xfd7zXZ\x00\x00\x01i\"\xde6\x02\x00!\x01\x08\x00\x00\x00\xd8\x0f#\x13\x01\xff\xff";

View file

@ -1204,12 +1204,10 @@ fn unpackResource(
},
.@"tar.xz" => {
const gpa = f.arena.child_allocator;
var dcp = std.compress.xz.decompress(gpa, resource.reader().adaptToOldInterface()) catch |err|
var decompress = std.compress.xz.Decompress.init(resource.reader(), gpa, &.{}) catch |err|
return f.fail(f.location_tok, try eb.printString("unable to decompress tarball: {t}", .{err}));
defer dcp.deinit();
var adapter_buffer: [1024]u8 = undefined;
var adapter = dcp.reader().adaptToNewApi(&adapter_buffer);
return try unpackTarball(f, tmp_directory.handle, &adapter.new_interface);
defer decompress.deinit();
return try unpackTarball(f, tmp_directory.handle, &decompress.reader);
},
.@"tar.zst" => {
const window_len = std.compress.zstd.default_window_len;