ceph/src/zstd/contrib/seekable_format/zstdseek_compress.c

   1 /*
   2  * Copyright (c) 2017-present, Facebook, Inc.
   3  * All rights reserved.
   4  *
   5  * This source code is licensed under both the BSD-style license (found in the
   6  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
   7  * in the COPYING file in the root directory of this source tree).
   8  */
   9
  10 #include <stdlib.h>     /* malloc, free */
  11
  12 #define XXH_STATIC_LINKING_ONLY
  13 #define XXH_NAMESPACE ZSTD_
  14 #include "xxhash.h"
  15
  16 #define ZSTD_STATIC_LINKING_ONLY
  17 #include "zstd.h"
  18 #include "zstd_errors.h"
  19 #include "mem.h"
  20 #include "zstd_seekable.h"
  21
  22 #define CHECK_Z(f) { size_t const ret = (f); if (ret != 0) return ret; }
  23
  24 #undef ERROR
  25 #define ERROR(name) ((size_t)-ZSTD_error_##name)
  26
  27 #undef MIN
  28 #undef MAX
  29 #define MIN(a, b) ((a) < (b) ? (a) : (b))
  30 #define MAX(a, b) ((a) > (b) ? (a) : (b))
  31
  32 typedef struct {
  33     U32 cSize;
  34     U32 dSize;
  35     U32 checksum;
  36 } framelogEntry_t;
  37
  38 struct ZSTD_frameLog_s {
  39     framelogEntry_t* entries;
  40     U32 size;
  41     U32 capacity;
  42
  43     int checksumFlag;
  44
  45     /* for use when streaming out the seek table */
  46     U32 seekTablePos;
  47     U32 seekTableIndex;
  48 } framelog_t;
  49
  50 struct ZSTD_seekable_CStream_s {
  51     ZSTD_CStream* cstream;
  52     ZSTD_frameLog framelog;
  53
  54     U32 frameCSize;
  55     U32 frameDSize;
  56
  57     XXH64_state_t xxhState;
  58
  59     U32 maxFrameSize;
  60
  61     int writingSeekTable;
  62 };
  63
  64 size_t ZSTD_seekable_frameLog_allocVec(ZSTD_frameLog* fl)
  65 {
  66     /* allocate some initial space */
  67     size_t const FRAMELOG_STARTING_CAPACITY = 16;
  68     fl->entries = (framelogEntry_t*)malloc(
  69             sizeof(framelogEntry_t) * FRAMELOG_STARTING_CAPACITY);
  70     if (fl->entries == NULL) return ERROR(memory_allocation);
  71     fl->capacity = FRAMELOG_STARTING_CAPACITY;
  72
  73     return 0;
  74 }
  75
  76 size_t ZSTD_seekable_frameLog_freeVec(ZSTD_frameLog* fl)
  77 {
  78     if (fl != NULL) free(fl->entries);
  79     return 0;
  80 }
  81
  82 ZSTD_frameLog* ZSTD_seekable_createFrameLog(int checksumFlag)
  83 {
  84     ZSTD_frameLog* fl = malloc(sizeof(ZSTD_frameLog));
  85     if (fl == NULL) return NULL;
  86
  87     if (ZSTD_isError(ZSTD_seekable_frameLog_allocVec(fl))) {
  88         free(fl);
  89         return NULL;
  90     }
  91
  92     fl->checksumFlag = checksumFlag;
  93     fl->seekTablePos = 0;
  94     fl->seekTableIndex = 0;
  95     fl->size = 0;
  96
  97     return fl;
  98 }
  99
 100 size_t ZSTD_seekable_freeFrameLog(ZSTD_frameLog* fl)
 101 {
 102     ZSTD_seekable_frameLog_freeVec(fl);
 103     free(fl);
 104     return 0;
 105 }
 106
 107 ZSTD_seekable_CStream* ZSTD_seekable_createCStream()
 108 {
 109     ZSTD_seekable_CStream* zcs = malloc(sizeof(ZSTD_seekable_CStream));
 110
 111     if (zcs == NULL) return NULL;
 112
 113     memset(zcs, 0, sizeof(*zcs));
 114
 115     zcs->cstream = ZSTD_createCStream();
 116     if (zcs->cstream == NULL) goto failed1;
 117
 118     if (ZSTD_isError(ZSTD_seekable_frameLog_allocVec(&zcs->framelog))) goto failed2;
 119
 120     return zcs;
 121
 122 failed2:
 123     ZSTD_freeCStream(zcs->cstream);
 124 failed1:
 125     free(zcs);
 126     return NULL;
 127 }
 128
 129 size_t ZSTD_seekable_freeCStream(ZSTD_seekable_CStream* zcs)
 130 {
 131     if (zcs == NULL) return 0; /* support free on null */
 132     ZSTD_freeCStream(zcs->cstream);
 133     ZSTD_seekable_frameLog_freeVec(&zcs->framelog);
 134     free(zcs);
 135
 136     return 0;
 137 }
 138
 139 size_t ZSTD_seekable_initCStream(ZSTD_seekable_CStream* zcs,
 140                                  int compressionLevel,
 141                                  int checksumFlag,
 142                                  U32 maxFrameSize)
 143 {
 144     zcs->framelog.size = 0;
 145     zcs->frameCSize = 0;
 146     zcs->frameDSize = 0;
 147
 148     /* make sure maxFrameSize has a reasonable value */
 149     if (maxFrameSize > ZSTD_SEEKABLE_MAX_FRAME_DECOMPRESSED_SIZE) {
 150         return ERROR(compressionParameter_unsupported);
 151     }
 152
 153     zcs->maxFrameSize = maxFrameSize
 154                                 ? maxFrameSize
 155                                 : ZSTD_SEEKABLE_MAX_FRAME_DECOMPRESSED_SIZE;
 156
 157     zcs->framelog.checksumFlag = checksumFlag;
 158     if (zcs->framelog.checksumFlag) {
 159         XXH64_reset(&zcs->xxhState, 0);
 160     }
 161
 162     zcs->framelog.seekTablePos = 0;
 163     zcs->framelog.seekTableIndex = 0;
 164     zcs->writingSeekTable = 0;
 165
 166     return ZSTD_initCStream(zcs->cstream, compressionLevel);
 167 }
 168
 169 size_t ZSTD_seekable_logFrame(ZSTD_frameLog* fl,
 170                                      unsigned compressedSize,
 171                                      unsigned decompressedSize,
 172                                      unsigned checksum)
 173 {
 174     if (fl->size == ZSTD_SEEKABLE_MAXFRAMES)
 175         return ERROR(frameIndex_tooLarge);
 176
 177     /* grow the buffer if required */
 178     if (fl->size == fl->capacity) {
 179         /* exponential size increase for constant amortized runtime */
 180         size_t const newCapacity = fl->capacity * 2;
 181         framelogEntry_t* const newEntries = realloc(fl->entries,
 182                 sizeof(framelogEntry_t) * newCapacity);
 183
 184         if (newEntries == NULL) return ERROR(memory_allocation);
 185
 186         fl->entries = newEntries;
 187         fl->capacity = newCapacity;
 188     }
 189
 190     fl->entries[fl->size] = (framelogEntry_t){
 191             compressedSize, decompressedSize, checksum
 192     };
 193     fl->size++;
 194
 195     return 0;
 196 }
 197
 198 size_t ZSTD_seekable_endFrame(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output)
 199 {
 200     size_t const prevOutPos = output->pos;
 201     /* end the frame */
 202     size_t ret = ZSTD_endStream(zcs->cstream, output);
 203
 204     zcs->frameCSize += output->pos - prevOutPos;
 205
 206     /* need to flush before doing the rest */
 207     if (ret) return ret;
 208
 209     /* frame done */
 210
 211     /* store the frame data for later */
 212     ret = ZSTD_seekable_logFrame(
 213             &zcs->framelog, zcs->frameCSize, zcs->frameDSize,
 214             zcs->framelog.checksumFlag
 215                     ? XXH64_digest(&zcs->xxhState) & 0xFFFFFFFFU
 216                     : 0);
 217     if (ret) return ret;
 218
 219     /* reset for the next frame */
 220     zcs->frameCSize = 0;
 221     zcs->frameDSize = 0;
 222
 223     ZSTD_resetCStream(zcs->cstream, 0);
 224     if (zcs->framelog.checksumFlag)
 225         XXH64_reset(&zcs->xxhState, 0);
 226
 227     return 0;
 228 }
 229
 230 size_t ZSTD_seekable_compressStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
 231 {
 232     const BYTE* const inBase = (const BYTE*) input->src + input->pos;
 233     size_t inLen = input->size - input->pos;
 234
 235     inLen = MIN(inLen, (size_t)(zcs->maxFrameSize - zcs->frameDSize));
 236
 237     /* if we haven't finished flushing the last frame, don't start writing a new one */
 238     if (inLen > 0) {
 239         ZSTD_inBuffer inTmp = { inBase, inLen, 0 };
 240         size_t const prevOutPos = output->pos;
 241
 242         size_t const ret = ZSTD_compressStream(zcs->cstream, output, &inTmp);
 243
 244         if (zcs->framelog.checksumFlag) {
 245             XXH64_update(&zcs->xxhState, inBase, inTmp.pos);
 246         }
 247
 248         zcs->frameCSize += output->pos - prevOutPos;
 249         zcs->frameDSize += inTmp.pos;
 250
 251         input->pos += inTmp.pos;
 252
 253         if (ZSTD_isError(ret)) return ret;
 254     }
 255
 256     if (zcs->maxFrameSize == zcs->frameDSize) {
 257         /* log the frame and start over */
 258         size_t const ret = ZSTD_seekable_endFrame(zcs, output);
 259         if (ZSTD_isError(ret)) return ret;
 260
 261         /* get the client ready for the next frame */
 262         return (size_t)zcs->maxFrameSize;
 263     }
 264
 265     return (size_t)(zcs->maxFrameSize - zcs->frameDSize);
 266 }
 267
 268 static inline size_t ZSTD_seekable_seekTableSize(const ZSTD_frameLog* fl)
 269 {
 270     size_t const sizePerFrame = 8 + (fl->checksumFlag?4:0);
 271     size_t const seekTableLen = ZSTD_skippableHeaderSize +
 272                                 sizePerFrame * fl->size +
 273                                 ZSTD_seekTableFooterSize;
 274
 275     return seekTableLen;
 276 }
 277
 278 static inline size_t ZSTD_stwrite32(ZSTD_frameLog* fl,
 279                                     ZSTD_outBuffer* output, U32 const value,
 280                                     U32 const offset)
 281 {
 282     if (fl->seekTablePos < offset + 4) {
 283         BYTE tmp[4]; /* so that we can work with buffers too small to write a whole word to */
 284         size_t const lenWrite =
 285                 MIN(output->size - output->pos, offset + 4 - fl->seekTablePos);
 286         MEM_writeLE32(tmp, value);
 287         memcpy((BYTE*)output->dst + output->pos,
 288                tmp + (fl->seekTablePos - offset), lenWrite);
 289         output->pos += lenWrite;
 290         fl->seekTablePos += lenWrite;
 291
 292         if (lenWrite < 4) return ZSTD_seekable_seekTableSize(fl) - fl->seekTablePos;
 293     }
 294     return 0;
 295 }
 296
 297 size_t ZSTD_seekable_writeSeekTable(ZSTD_frameLog* fl, ZSTD_outBuffer* output)
 298 {
 299     /* seekTableIndex: the current index in the table and
 300      * seekTableSize: the amount of the table written so far
 301      *
 302      * This function is written this way so that if it has to return early
 303      * because of a small buffer, it can keep going where it left off.
 304      */
 305
 306     size_t const sizePerFrame = 8 + (fl->checksumFlag?4:0);
 307     size_t const seekTableLen = ZSTD_seekable_seekTableSize(fl);
 308
 309     CHECK_Z(ZSTD_stwrite32(fl, output, ZSTD_MAGIC_SKIPPABLE_START | 0xE, 0));
 310     CHECK_Z(ZSTD_stwrite32(fl, output, seekTableLen - ZSTD_skippableHeaderSize,
 311                            4));
 312
 313     while (fl->seekTableIndex < fl->size) {
 314         CHECK_Z(ZSTD_stwrite32(fl, output,
 315                                fl->entries[fl->seekTableIndex].cSize,
 316                                ZSTD_skippableHeaderSize +
 317                                        sizePerFrame * fl->seekTableIndex + 0));
 318
 319         CHECK_Z(ZSTD_stwrite32(fl, output,
 320                                fl->entries[fl->seekTableIndex].dSize,
 321                                ZSTD_skippableHeaderSize +
 322                                        sizePerFrame * fl->seekTableIndex + 4));
 323
 324         if (fl->checksumFlag) {
 325             CHECK_Z(ZSTD_stwrite32(
 326                     fl, output, fl->entries[fl->seekTableIndex].checksum,
 327                     ZSTD_skippableHeaderSize +
 328                             sizePerFrame * fl->seekTableIndex + 8));
 329         }
 330
 331         fl->seekTableIndex++;
 332     }
 333
 334     CHECK_Z(ZSTD_stwrite32(fl, output, fl->size,
 335                            seekTableLen - ZSTD_seekTableFooterSize));
 336
 337     if (output->size - output->pos < 1) return seekTableLen - fl->seekTablePos;
 338     if (fl->seekTablePos < seekTableLen - 4) {
 339         BYTE sfd = 0;
 340         sfd |= (fl->checksumFlag) << 7;
 341
 342         ((BYTE*)output->dst)[output->pos] = sfd;
 343         output->pos++;
 344         fl->seekTablePos++;
 345     }
 346
 347     CHECK_Z(ZSTD_stwrite32(fl, output, ZSTD_SEEKABLE_MAGICNUMBER,
 348                            seekTableLen - 4));
 349
 350     if (fl->seekTablePos != seekTableLen) return ERROR(GENERIC);
 351     return 0;
 352 }
 353
 354 size_t ZSTD_seekable_endStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output)
 355 {
 356     if (!zcs->writingSeekTable && zcs->frameDSize) {
 357         const size_t endFrame = ZSTD_seekable_endFrame(zcs, output);
 358         if (ZSTD_isError(endFrame)) return endFrame;
 359         /* return an accurate size hint */
 360         if (endFrame) return endFrame + ZSTD_seekable_seekTableSize(&zcs->framelog);
 361     }
 362
 363     zcs->writingSeekTable = 1;
 364
 365     return ZSTD_seekable_writeSeekTable(&zcs->framelog, output);
 366 }