diff options
Diffstat (limited to 'research/brotli_decoder.c')
-rw-r--r-- | research/brotli_decoder.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/research/brotli_decoder.c b/research/brotli_decoder.c new file mode 100644 index 0000000..b1d556d --- /dev/null +++ b/research/brotli_decoder.c @@ -0,0 +1,93 @@ +/* Copyright 2018 Google Inc. All Rights Reserved. + + Distributed under MIT license. + See file LICENSE for detail or copy at https://opensource.org/licenses/MIT +*/ + +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +#include <brotli/decode.h> + +#define BUFFER_SIZE (1u << 20) + +typedef struct Context { + FILE* fin; + FILE* fout; + uint8_t* input_buffer; + uint8_t* output_buffer; + BrotliDecoderState* decoder; +} Context; + +void init(Context* ctx) { + ctx->fin = 0; + ctx->fout = 0; + ctx->input_buffer = 0; + ctx->output_buffer = 0; + ctx->decoder = 0; +} + +void cleanup(Context* ctx) { + if (ctx->decoder) BrotliDecoderDestroyInstance(ctx->decoder); + if (ctx->output_buffer) free(ctx->output_buffer); + if (ctx->input_buffer) free(ctx->input_buffer); + if (ctx->fout) fclose(ctx->fout); + if (ctx->fin) fclose(ctx->fin); +} + +void fail(Context* ctx, const char* message) { + fprintf(stderr, "%s\n", message); + exit(1); +} + +int main(int argc, char** argv) { + Context ctx; + BrotliDecoderResult result = BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT; + size_t available_in; + const uint8_t* next_in; + size_t available_out = BUFFER_SIZE; + uint8_t* next_out; + init(&ctx); + + ctx.fin = fdopen(STDIN_FILENO, "rb"); + if (!ctx.fin) fail(&ctx, "can't open input file"); + ctx.fout = fdopen(STDOUT_FILENO, "wb"); + if (!ctx.fout) fail(&ctx, "can't open output file"); + ctx.input_buffer = (uint8_t*)malloc(BUFFER_SIZE); + if (!ctx.input_buffer) fail(&ctx, "out of memory / input buffer"); + ctx.output_buffer = (uint8_t*)malloc(BUFFER_SIZE); + if (!ctx.output_buffer) fail(&ctx, "out of memory / output buffer"); + ctx.decoder = BrotliDecoderCreateInstance(0, 0, 0); + if (!ctx.decoder) fail(&ctx, "out of memory / decoder"); + BrotliDecoderSetParameter(ctx.decoder, BROTLI_DECODER_PARAM_LARGE_WINDOW, 1); + + next_out = ctx.output_buffer; + while (1) { + if (result == BROTLI_DECODER_RESULT_NEEDS_MORE_INPUT) { + if (feof(ctx.fin)) break; + available_in = fread(ctx.input_buffer, 1, BUFFER_SIZE, ctx.fin); + next_in = ctx.input_buffer; + if (ferror(ctx.fin)) break; + } else if (result == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) { + fwrite(ctx.output_buffer, 1, BUFFER_SIZE, ctx.fout); + if (ferror(ctx.fout)) break; + available_out = BUFFER_SIZE; + next_out = ctx.output_buffer; + } else { + break; + } + result = BrotliDecoderDecompressStream( + ctx.decoder, &available_in, &next_in, &available_out, &next_out, 0); + } + if (next_out != ctx.output_buffer) { + fwrite(ctx.output_buffer, 1, next_out - ctx.output_buffer, ctx.fout); + } + if ((result == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT) || ferror(ctx.fout)) { + fail(&ctx, "failed to write output"); + } else if (result != BROTLI_DECODER_RESULT_SUCCESS) { + fail(&ctx, "corrupt input"); + } + cleanup(&ctx); + return 0; +} |