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4.5 kB · 125 lines
Zig
at main
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126const std = @import("std");
const c = @cImport({ @cInclude("zlib.h");});
const Allocator = std.mem.Allocator;
pub const Error = error{ CompressionInitFailed, CompressionFailed, CompressionResetFailed, DecompressionInitFailed, DecompressionFailed, DecompressionResetFailed, InvalidCompressionTail,};
pub const Compressor = struct { stream: c.z_stream,
pub fn init(self: *Compressor) Error!void { self.stream = std.mem.zeroes(c.z_stream); if (c.deflateInit2( &self.stream, c.Z_DEFAULT_COMPRESSION, c.Z_DEFLATED, -c.MAX_WBITS, 8, c.Z_DEFAULT_STRATEGY, ) != c.Z_OK) return error.CompressionInitFailed; }
pub fn deinit(self: *Compressor) void { _ = c.deflateEnd(&self.stream); }
pub fn reset(self: *Compressor) Error!void { if (c.deflateReset(&self.stream) != c.Z_OK) return error.CompressionResetFailed; }
pub fn compress( self: *Compressor, allocator: Allocator, input: []const u8, output: *std.ArrayList(u8), ) (Allocator.Error || Error)![]const u8 { output.clearRetainingCapacity(); var input_offset: usize = 0; while (true) { if (self.stream.avail_in == 0 and input_offset < input.len) { const n = @min(input.len - input_offset, std.math.maxInt(c.uInt)); self.stream.next_in = @constCast(input[input_offset..].ptr); self.stream.avail_in = @intCast(n); input_offset += n; }
try output.ensureUnusedCapacity(allocator, 16 * 1024); const writable = output.unusedCapacitySlice(); const capacity = @min(writable.len, std.math.maxInt(c.uInt)); self.stream.next_out = writable.ptr; self.stream.avail_out = @intCast(capacity); const flush: c_int = if (input_offset == input.len) c.Z_SYNC_FLUSH else c.Z_NO_FLUSH; const result = c.deflate(&self.stream, flush); if (result != c.Z_OK) return error.CompressionFailed; const written = capacity - self.stream.avail_out; output.items.len += written;
if (flush == c.Z_SYNC_FLUSH and self.stream.avail_in == 0 and self.stream.avail_out != 0) break; }
const tail = "\x00\x00\xff\xff"; if (output.items.len < tail.len or !std.mem.eql(u8, output.items[output.items.len - tail.len ..], tail)) return error.InvalidCompressionTail; output.items.len -= tail.len; return output.items; }};
pub const Decompressor = struct { stream: c.z_stream,
pub fn init(self: *Decompressor) Error!void { self.stream = std.mem.zeroes(c.z_stream); if (c.inflateInit2(&self.stream, -c.MAX_WBITS) != c.Z_OK) return error.DecompressionInitFailed; }
pub fn deinit(self: *Decompressor) void { _ = c.inflateEnd(&self.stream); }
pub fn reset(self: *Decompressor) Error!void { if (c.inflateReset(&self.stream) != c.Z_OK) return error.DecompressionResetFailed; }
pub fn decompress(self: *Decompressor, input: []const u8, output: anytype) Error!void { var input_offset: usize = 0; var chunk: [16 * 1024]u8 = undefined; while (true) { if (self.stream.avail_in == 0 and input_offset < input.len) { const n = @min(input.len - input_offset, std.math.maxInt(c.uInt)); self.stream.next_in = @constCast(input[input_offset..].ptr); self.stream.avail_in = @intCast(n); input_offset += n; } self.stream.next_out = &chunk; self.stream.avail_out = chunk.len; const result = c.inflate(&self.stream, c.Z_SYNC_FLUSH); if (result != c.Z_OK and result != c.Z_BUF_ERROR) return error.DecompressionFailed; const written = chunk.len - self.stream.avail_out; output.writeAll(chunk[0..written]) catch return error.DecompressionFailed;
if (input_offset == input.len and self.stream.avail_in == 0 and self.stream.avail_out != 0) break; if (written == 0 and self.stream.avail_in == 0 and input_offset == input.len) return error.DecompressionFailed; } }};