lib/got_lib_deltify.h

   1 /*
   2  * Copyright (c) 2020 Ori Bernstein
   3  * Copyright (c) 2021 Stefan Sperling <stsp@openbsd.org>
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 struct got_delta_block {
  19         off_t           len;
  20         off_t           offset;
  21         uint32_t        hash;
  22 };
  23
  24 struct got_delta_table {
  25         struct got_delta_block  *blocks;
  26         int                     nblocks;
  27         int                     nalloc;
  28 };
  29
  30 struct got_delta_instruction {
  31         int     copy;
  32         off_t   offset;
  33         off_t   len;
  34 };
  35
  36 enum {
  37         GOT_DELTIFY_MINCHUNK    = 32,
  38         GOT_DELTIFY_MAXCHUNK    = 8192,
  39         GOT_DELTIFY_SPLITMASK   = (1 << 8) - 1,
  40 };
  41
  42 const struct got_error *got_deltify_init(struct got_delta_table **dt, FILE *f,
  43     off_t fileoffset, off_t filesize, uint32_t seed);
  44 const struct got_error *got_deltify_init_mem(struct got_delta_table **dt,
  45     uint8_t *data, off_t fileoffset, off_t filesize, uint32_t seed);
  46 const struct got_error *got_deltify(struct got_delta_instruction **deltas,
  47     int *ndeltas, FILE *f, off_t fileoffset, off_t filesize, uint32_t seed,
  48     struct got_delta_table *dt, FILE *basefile, off_t basefile_offset0,
  49     off_t basefile_size);
  50 const struct got_error *got_deltify_file_mem(
  51     struct got_delta_instruction **deltas, int *ndeltas,
  52     FILE *f, off_t fileoffset, off_t filesize, uint32_t seed,
  53     struct got_delta_table *dt, uint8_t *basedata, off_t basefile_offset0,
  54     off_t basefile_size);
  55 const struct got_error *got_deltify_mem_file(
  56     struct got_delta_instruction **deltas, int *ndeltas,
  57     uint8_t *data, off_t fileoffset, off_t filesize, uint32_t seed,
  58     struct got_delta_table *dt, FILE *basefile, off_t basefile_offset0,
  59     off_t basefile_size);
  60 const struct got_error *got_deltify_mem_mem(
  61     struct got_delta_instruction **deltas, int *ndeltas,
  62     uint8_t *data, off_t fileoffset, off_t filesize, uint32_t seed,
  63     struct got_delta_table *dt, uint8_t *basedata, off_t basefile_offset0,
  64     off_t basefile_size);
  65 void got_deltify_free(struct got_delta_table *dt);