wrap vendored zstd seekable in own file, #2

laumann

May 13, 2023, 10:34 AM

L3HKOF4WYZZLJJY2Q6YJ65WGAB74GQ2A7ICD23M5NQGBP4BXF6DQC

Dependencies

• [2] CYS4NENL move zstdseek files to vendor/zstdseek
• [3] XTKRT6OQ format the codebase
• [4] XJ2PEH74 add meson.build
• [5] RIWSVVAS change: decompress the 'contents' with zstd_seekable
• [6] OBKF6SII change: decompress the hashed section too
• [7] KEC3WLFN change: remove debugging lines
• [8] 2C2EF2GK move blake3 files to vendor/blake3
• [9] Y26WT3ZF change: decode message, description and timestamp
• [10] KDJUAAAL change: prefix function names with change_
• [11] NZNIG2UL Fix lots of warnings, adjust build flags
• [12] Q7TKZCJP Add initial support for reading the offsets from a (fixed) change
• [13] 2U7P5SFQ Change struct names "struct foo -> typedef struct Foo"
• [14] WMFNGOYT change: reduce printed noise, rework some code
• [15] U3JWO63Y change: deduplicate some code repetition
• [*] PEUS54XQ

Change contents

• file addition: zstdseek.h (----------)
  [17.1]
  + #ifndef ANI_ZSTDSEEK_H

  + #define ANI_ZSTDSEEK_H

  +

  + /* Wrapper layer for working with the seekable variant of zstd. */

  + size_t zstdseek_decompress(uint8_t *, size_t, uint8_t *, size_t);

  +

  + #endif
• file addition: zstdseek.c (----------)
  [17.1]
  + #include <stdint.h>

  + #include <stdio.h>

  + #include <zstd.h>

  +

  + #include "zstdseek.h"

  + #include "vendor/zstdseek/zstd_seekable.h"

  +

  + /**

  + * Returns zero if decompression fails, non-zero otherwise.

  + */

  + size_t

  + zstdseek_decompress(

  + uint8_t *dest, size_t expected_len, uint8_t *compressed,

  + size_t compressed_len

  + )

  + {

  + ZSTD_seekable *zs;

  + size_t result;

  +

  + result = 0;

  + zs = ZSTD_seekable_create();

  + if (zs == NULL) {

  + fprintf(stderr, "ZSTD_seekable_create() failed");

  + goto out;

  + }

  +

  + result = ZSTD_seekable_initBuff(zs, compressed, compressed_len);

  + if (ZSTD_isError(result)) {

  + fprintf(stderr, "ZSTD_seekable_init() error: %s\n",

  + ZSTD_getErrorName(result));

  + result = 0;

  + goto outfreezs;

  + }

  +

  + result = ZSTD_seekable_decompress(zs, dest, expected_len, 0);

  + printf("decompress result: %lu\n", result);

  + if (ZSTD_isError(result)) {

  + fprintf(stderr, "ZSTD_seekable_decompress() error: %s\n",

  + ZSTD_getErrorName(result));

  + result = 0;

  + goto outfreezs;

  + }

  + if (result != expected_len) {

  + fprintf(stderr, "decoded %lu bytes, wanted %lu\n", result,

  + expected_len);

  + result = 0;

  + }

  + outfreezs:

  + ZSTD_seekable_free(zs);

  + out:

  + return result;

  + }
• replacement in meson.build at line 29
  [4.346]→[4.346:357](∅→∅)
  − 'hunk.c'
  [4.346]

  [4.357]
  + 'hunk.c',

  + 'zstdseek.c',
• edit in change.c at line 8
  [5.20]→[5.20:38](∅→∅)
  − #include <zstd.h>
• replacement in change.c at line 11
  [5.596]→[2.226:269](∅→∅)
  − #include "vendor/zstdseek/zstd_seekable.h"
  [5.596]

  [5.285666]
  + #include "zstdseek.h"
• edit in change.c at line 91
  [5.904]→[5.904:924](∅→∅)
  − ZSTD_seekable *zs;
• replacement in change.c at line 112
  [5.1632]→[5.1632:1751](∅→∅)
  − zs = ZSTD_seekable_create();

  − if (zs == NULL) {

  − fprintf(stderr, "ZSTD_seekable_create() failed");

  − goto errout;

  − }
  [5.1632]

  [5.1751]
  + result = zstdseek_decompress(

  + buf, expected_len, compressed, compressed_len

  + );

  + if (result)

  + goto out;
• edit in change.c at line 118
  [5.1752]→[5.827:893](∅→∅),[5.893]→[5.1822:1905](∅→∅),[5.1822]→[5.1822:1905](∅→∅),[5.1905]→[3.841:872](∅→∅),[3.872]→[5.1937:1959](∅→∅),[5.1937]→[5.1937:1959](∅→∅),[5.1959]→[5.894:956](∅→∅),[5.956]→[5.2026:2160](∅→∅),[5.2026]→[5.2026:2160](∅→∅),[5.2160]→[3.873:904](∅→∅),[3.904]→[5.2192:2213](∅→∅),[5.2192]→[5.2192:2213](∅→∅),[5.2213]→[5.957:988](∅→∅),[5.988]→[3.905:984](∅→∅),[3.984]→[5.2330:2351](∅→∅),[5.1064]→[5.2330:2351](∅→∅),[5.2330]→[5.2330:2351](∅→∅),[5.2447]→[5.2447:2521](∅→∅)
  − result = ZSTD_seekable_initBuff(zs, compressed, compressed_len);

  − if (ZSTD_isError(result)) {

  − fprintf(stderr, "ZSTD_seekable_init() error: %s\n",

  − ZSTD_getErrorName(result));

  − goto outfreezs;

  − }

  −

  − result = ZSTD_seekable_decompress(zs, buf, expected_len, 0);

  − printf("decompress result: %lu\n", result);

  − if (ZSTD_isError(result)) {

  − fprintf(stderr, "ZSTD_seekable_decompress() error: %s\n",

  − ZSTD_getErrorName(result));

  − goto outfreezs;

  − }

  − if (result != expected_len) {

  − fprintf(stderr, "decoded %lu bytes, wanted %lu\n", result,

  − expected_len);

  − goto outfreezs;

  − }

  −

  − ZSTD_seekable_free(zs);

  − goto out;

  −

  − outfreezs:

  − ZSTD_seekable_free(zs);