126 lines
2.5 KiB
C
126 lines
2.5 KiB
C
#include "mupdf/fitz.h"
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#include <zlib.h>
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#include <string.h>
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typedef struct fz_inflate_state_s fz_inflate_state;
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struct fz_inflate_state_s
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{
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fz_stream *chain;
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z_stream z;
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unsigned char buffer[4096];
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};
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void *fz_zlib_alloc(void *ctx, unsigned int items, unsigned int size)
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{
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return fz_malloc_no_throw(ctx, items * size);
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}
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void fz_zlib_free(void *ctx, void *ptr)
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{
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fz_free(ctx, ptr);
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}
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static int
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next_flated(fz_context *ctx, fz_stream *stm, size_t required)
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{
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fz_inflate_state *state = stm->state;
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fz_stream *chain = state->chain;
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z_streamp zp = &state->z;
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int code;
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unsigned char *outbuf = state->buffer;
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int outlen = sizeof(state->buffer);
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if (stm->eof)
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return EOF;
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zp->next_out = outbuf;
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zp->avail_out = outlen;
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while (zp->avail_out > 0)
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{
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zp->avail_in = (uInt)fz_available(ctx, chain, 1);
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zp->next_in = chain->rp;
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code = inflate(zp, Z_SYNC_FLUSH);
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chain->rp = chain->wp - zp->avail_in;
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if (code == Z_STREAM_END)
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{
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break;
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}
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else if (code == Z_BUF_ERROR)
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{
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fz_warn(ctx, "premature end of data in flate filter");
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break;
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}
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else if (code == Z_DATA_ERROR && zp->avail_in == 0)
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{
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fz_warn(ctx, "ignoring zlib error: %s", zp->msg);
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break;
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}
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else if (code == Z_DATA_ERROR && !strcmp(zp->msg, "incorrect data check"))
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{
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fz_warn(ctx, "ignoring zlib error: %s", zp->msg);
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chain->rp = chain->wp;
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break;
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}
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else if (code != Z_OK)
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{
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fz_throw(ctx, FZ_ERROR_GENERIC, "zlib error: %s", zp->msg);
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}
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}
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stm->rp = state->buffer;
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stm->wp = state->buffer + outlen - zp->avail_out;
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stm->pos += outlen - zp->avail_out;
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if (stm->rp == stm->wp)
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{
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stm->eof = 1;
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return EOF;
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}
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return *stm->rp++;
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}
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static void
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close_flated(fz_context *ctx, void *state_)
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{
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fz_inflate_state *state = (fz_inflate_state *)state_;
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int code;
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code = inflateEnd(&state->z);
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if (code != Z_OK)
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fz_warn(ctx, "zlib error: inflateEnd: %s", state->z.msg);
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fz_drop_stream(ctx, state->chain);
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fz_free(ctx, state);
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}
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fz_stream *
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fz_open_flated(fz_context *ctx, fz_stream *chain, int window_bits)
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{
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fz_inflate_state *state;
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int code;
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state = fz_malloc_struct(ctx, fz_inflate_state);
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state->z.zalloc = fz_zlib_alloc;
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state->z.zfree = fz_zlib_free;
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state->z.opaque = ctx;
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state->z.next_in = NULL;
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state->z.avail_in = 0;
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code = inflateInit2(&state->z, window_bits);
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if (code != Z_OK)
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{
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fz_free(ctx, state);
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fz_throw(ctx, FZ_ERROR_GENERIC, "zlib error: inflateInit2 failed");
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}
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state->chain = fz_keep_stream(ctx, chain);
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return fz_new_stream(ctx, state, next_flated, close_flated);
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}
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