static const ZSTD_DDict* createDict(const char* dictFileName)
{
size_t dictSize;
void* const dictBuffer = loadFileX(dictFileName, &dictSize);
const ZSTD_DDict* const ddict = ZSTD_createDDict(dictBuffer, dictSize);
free(dictBuffer);
return ddict;
}
/* createDict() :
`dictFileName` is supposed to have been created using `zstd --train` */
static ZSTD_DDict* createDict_orDie(const char* dictFileName)
{
size_t dictSize;
printf("loading dictionary %s \n", dictFileName);
void* const dictBuffer = loadFile_orDie(dictFileName, &dictSize);
ZSTD_DDict* const ddict = ZSTD_createDDict(dictBuffer, dictSize);
if (ddict==NULL) { fprintf(stderr, "ZSTD_createDDict error \n"); exit(5); }
free(dictBuffer);
return ddict;
}
struct solv_zchunk *
solv_zchunk_open(FILE *fp, unsigned int streamid)
{
struct solv_zchunk *zck;
unsigned char *p;
unsigned int hdr_size; /* preface + index + signatures */
unsigned int lead_size;
unsigned int preface_size;
unsigned int index_size;
zck = solv_calloc(1, sizeof(*zck));
/* read and parse the lead, read the complete header */
zck->hdr = solv_calloc(15, 1);
zck->hdr_end = zck->hdr + 15;
if (fread(zck->hdr, 15, 1, fp) != 1 || memcmp(zck->hdr, "\000ZCK1", 5) != 0)
return open_error(zck);
p = zck->hdr + 5;
if ((p = getchksum(p, zck->hdr_end, &zck->hdr_chk_type, &zck->hdr_chk_len, &zck->hdr_chk_id)) == 0)
return open_error(zck);
if ((p = getuint(p, zck->hdr_end, &hdr_size)) == 0 || hdr_size > MAX_HDR_SIZE)
return open_error(zck);
lead_size = p - zck->hdr + zck->hdr_chk_len;
zck->hdr = solv_realloc(zck->hdr, lead_size + hdr_size);
zck->hdr_end = zck->hdr + lead_size + hdr_size;
if (fread(zck->hdr + 15, lead_size + hdr_size - 15, 1, fp) != 1)
return open_error(zck);
/* verify header checksum to guard against corrupt files */
if (zck->hdr_chk_id)
{
Chksum *chk = solv_chksum_create(zck->hdr_chk_id);
if (!chk)
return open_error(zck);
solv_chksum_add(chk, zck->hdr, lead_size - zck->hdr_chk_len);
solv_chksum_add(chk, zck->hdr + lead_size, hdr_size);
if (memcmp(solv_chksum_get(chk, 0), zck->hdr + (lead_size - zck->hdr_chk_len), zck->hdr_chk_len) != 0)
{
solv_chksum_free(chk, 0);
return open_error(zck);
}
solv_chksum_free(chk, 0);
}
/* parse preface: data chksum, flags, compression */
p = zck->hdr + lead_size;
if (p + zck->hdr_chk_len > zck->hdr_end)
return open_error(zck);
zck->data_chk_ptr = p;
p += zck->hdr_chk_len;
#ifdef VERIFY_DATA_CHKSUM
if (zck->hdr_chk_id && (zck->data_chk = solv_chksum_create(zck->hdr_chk_id)) == 0)
return open_error(zck);
#endif
if ((p = getuint(p, zck->hdr_end, &zck->flags)) == 0)
return open_error(zck);
if ((zck->flags & ~(3)) != 0)
return open_error(zck);
if ((p = getuint(p, zck->hdr_end, &zck->comp)) == 0 || (zck->comp != 0 && zck->comp != 2))
return open_error(zck); /* only uncompressed + zstd supported */
/* skip all optional elements if present */
if ((zck->flags & 2) != 0)
{
unsigned int nopt, lopt;
if ((p = getuint(p, zck->hdr_end, &nopt)) == 0)
return open_error(zck);
for (; nopt != 0; nopt--)
{
if ((p = getuint(p, zck->hdr_end, &lopt)) == 0)
return open_error(zck);
if ((p = getuint(p, zck->hdr_end, &lopt)) == 0)
return open_error(zck);
if (p + lopt > zck->hdr_end)
return open_error(zck);
p += lopt;
}
}
preface_size = p - (zck->hdr + lead_size);
/* parse index: index size, index chksum type, num chunks, chunk data */
if ((p = getuint(p, zck->hdr_end, &index_size)) == 0)
return open_error(zck);
if (hdr_size < preface_size + index_size)
return open_error(zck);
if ((p = getchksum(p, zck->hdr_end, &zck->chunk_chk_type, &zck->chunk_chk_len, &zck->chunk_chk_id)) == 0)
return open_error(zck);
if ((p = getuint(p, zck->hdr_end, &zck->nchunks)) == 0 || zck->nchunks > MAX_CHUNK_CNT)
return open_error(zck);
/* setup decompressor */
if (zck->comp == 2)
{
if ((zck->dctx = ZSTD_createDCtx()) == 0)
return open_error(zck);
}
zck->fp = fp;
zck->chunks = p;
zck->streamid = streamid;
if (streamid == 0)
{
zck->nchunks = zck->nchunks ? 1 : 0; /* limit to dict chunk */
return zck;
}
/* setup dictionary */
if (!nextchunk(zck, 0))
{
zck->fp = 0;
return open_error(zck);
}
if (zck->comp == 2 && zck->buf_avail)
{
if ((zck->ddict = ZSTD_createDDict(zck->buf, zck->buf_avail)) == 0)
{
zck->fp = 0;
return open_error(zck);
}
}
zck->buf = solv_free(zck->buf);
zck->buf_used = 0;
zck->buf_avail = 0;
/* ready to read the rest of the chunks */
return zck;
}
