diff options
Diffstat (limited to 'xlators/features/compress/src/cdc-helper.c')
| -rw-r--r-- | xlators/features/compress/src/cdc-helper.c | 547 |
1 files changed, 547 insertions, 0 deletions
diff --git a/xlators/features/compress/src/cdc-helper.c b/xlators/features/compress/src/cdc-helper.c new file mode 100644 index 00000000000..54432ff455c --- /dev/null +++ b/xlators/features/compress/src/cdc-helper.c @@ -0,0 +1,547 @@ +/* + Copyright (c) 2013 Red Hat, Inc. <http://www.redhat.com> + This file is part of GlusterFS. + + This file is licensed to you under your choice of the GNU Lesser + General Public License, version 3 or any later version (LGPLv3 or + later), or the GNU General Public License, version 2 (GPLv2), in all + cases as published by the Free Software Foundation. +*/ + +#ifndef _CONFIG_H +#define _CONFIG_H +#include "config.h" +#endif + +#include "glusterfs.h" +#include "logging.h" + +#include "cdc.h" +#include "cdc-mem-types.h" + +#ifdef HAVE_LIB_Z +#include "zlib.h" +#endif + +#ifdef HAVE_LIB_Z +/* gzip header looks something like this + * (RFC 1950) + * + * +---+---+---+---+---+---+---+---+---+---+ + * |ID1|ID2|CM |FLG| MTIME |XFL|OS | + * +---+---+---+---+---+---+---+---+---+---+ + * + * Data is usually sent without this header i.e + * Data sent = <compressed-data> + trailer(8) + * The trailer contains the checksum. + * + * gzip_header is added only during debugging. + * Refer to the function cdc_dump_iovec_to_disk + */ +static const char gzip_header[10] = + { + '\037', '\213', Z_DEFLATED, 0, + 0, 0, 0, 0, + 0, GF_CDC_OS_ID + }; + +static int32_t +cdc_next_iovec (xlator_t *this, cdc_info_t *ci) +{ + int ret = -1; + + ci->ncount++; + /* check for iovec overflow -- should not happen */ + if (ci->ncount == MAX_IOVEC) { + gf_log (this->name, GF_LOG_ERROR, + "Zlib output buffer overflow" + " ->ncount (%d) | ->MAX_IOVEC (%d)", + ci->ncount, MAX_IOVEC); + goto out; + } + + ret = 0; + + out: + return ret; +} + +static void +cdc_put_long (unsigned char *string, unsigned long x) +{ + string[0] = (unsigned char) (x & 0xff); + string[1] = (unsigned char) ((x & 0xff00) >> 8); + string[2] = (unsigned char) ((x & 0xff0000) >> 16); + string[3] = (unsigned char) ((x & 0xff000000) >> 24); +} + +static unsigned long +cdc_get_long (unsigned char *buf) +{ + return ((unsigned long) buf[0]) + | (((unsigned long) buf[1]) << 8) + | (((unsigned long) buf[2]) << 16) + | (((unsigned long) buf[3]) << 24); +} + +static int32_t +cdc_init_gzip_trailer (xlator_t *this, cdc_priv_t *priv, cdc_info_t *ci) +{ + int ret = -1; + char *buf = NULL; + + ret = cdc_next_iovec (this, ci); + if (ret) + goto out; + + buf = CURR_VEC(ci).iov_base = + (char *) GF_CALLOC (1, GF_CDC_VALIDATION_SIZE, + gf_cdc_mt_gzip_trailer_t); + + if (!CURR_VEC(ci).iov_base) + goto out; + + CURR_VEC(ci).iov_len = GF_CDC_VALIDATION_SIZE; + + cdc_put_long ((unsigned char *)&buf[0], ci->crc); + cdc_put_long ((unsigned char *)&buf[4], ci->stream.total_in); + + ret = 0; + + out: + return ret; +} + +static int32_t +cdc_alloc_iobuf_and_init_vec (xlator_t *this, + cdc_priv_t *priv, cdc_info_t *ci, + int size) +{ + int ret = -1; + int alloc_len = 0; + struct iobuf *iobuf = NULL; + + ret = cdc_next_iovec (this, ci); + if (ret) + goto out; + + alloc_len = size ? size : ci->buffer_size; + + iobuf = iobuf_get2 (this->ctx->iobuf_pool, alloc_len); + if (!iobuf) + goto out; + + ret = iobref_add (ci->iobref, iobuf); + if (ret) + goto out; + + /* Initialize this iovec */ + CURR_VEC(ci).iov_base = iobuf->ptr; + CURR_VEC(ci).iov_len = alloc_len; + + ret = 0; + + out: + return ret; +} + +static void +cdc_init_zlib_output_stream (cdc_priv_t *priv, cdc_info_t *ci, int size) +{ + ci->stream.next_out = (unsigned char *) CURR_VEC(ci).iov_base; + ci->stream.avail_out = size ? size : ci->buffer_size; +} + +/* This routine is for testing and debugging only. + * Data written = header(10) + <compressed-data> + trailer(8) + * So each gzip dump file is at least 18 bytes in size. + */ +void +cdc_dump_iovec_to_disk (xlator_t *this, cdc_info_t *ci, const char *file) +{ + int i = 0; + int fd = 0; + size_t writen = 0; + size_t total_writen = 0; + + fd = open (file, O_WRONLY|O_CREAT|O_TRUNC, 0777 ); + if (fd < 0) { + gf_log (this->name, GF_LOG_ERROR, + "Cannot open file: %s", file); + return; + } + + writen = write (fd, (char *) gzip_header, 10); + total_writen += writen; + for (i = 0; i < ci->ncount; i++) { + writen = write (fd, (char *) ci->vec[i].iov_base, ci->vec[i].iov_len); + total_writen += writen; + } + + gf_log (this->name, GF_LOG_DEBUG, + "dump'd %zu bytes to %s", total_writen, GF_CDC_DEBUG_DUMP_FILE ); + + close (fd); +} + +static int32_t +cdc_flush_libz_buffer (cdc_priv_t *priv, xlator_t *this, cdc_info_t *ci, + int (*libz_func)(z_streamp, int), + int flush) +{ + int32_t ret = Z_OK; + int done = 0; + unsigned int deflate_len = 0; + + for (;;) { + deflate_len = ci->buffer_size - ci->stream.avail_out; + + if (deflate_len != 0) { + CURR_VEC(ci).iov_len = deflate_len; + + ret = cdc_alloc_iobuf_and_init_vec (this, priv, ci, 0); + if (ret) { + ret = Z_MEM_ERROR; + break; + } + + /* Re-position Zlib output buffer */ + cdc_init_zlib_output_stream (priv, ci, 0); + } + + if (done) { + ci->ncount--; + break; + } + + ret = libz_func (&ci->stream, flush); + + if (ret == Z_BUF_ERROR) { + ret = Z_OK; + ci->ncount--; + break; + } + + done = (ci->stream.avail_out != 0 || ret == Z_STREAM_END); + + if (ret != Z_OK && ret != Z_STREAM_END) + break; + } + + return ret; +} + +static int32_t +do_cdc_compress (struct iovec *vec, xlator_t *this, cdc_priv_t *priv, + cdc_info_t *ci) +{ + int ret = -1; + + /* Initialize defalte */ + ret = deflateInit2 (&ci->stream, priv->cdc_level, Z_DEFLATED, + priv->window_size, priv->mem_level, + Z_DEFAULT_STRATEGY); + + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "unable to init Zlib (retval: %d)", ret); + goto out; + } + + ret = cdc_alloc_iobuf_and_init_vec (this, priv, ci, 0); + if (ret) + goto out; + + /* setup output buffer */ + cdc_init_zlib_output_stream (priv, ci, 0); + + /* setup input buffer */ + ci->stream.next_in = (unsigned char *) vec->iov_base; + ci->stream.avail_in = vec->iov_len; + + ci->crc = crc32 (ci->crc, (const Bytef *) vec->iov_base, vec->iov_len); + + gf_log (this->name, GF_LOG_DEBUG, "crc=%lu len=%d buffer_size=%d", + ci->crc, ci->stream.avail_in, ci->buffer_size); + + /* compress !! */ + while (ci->stream.avail_in != 0) { + if (ci->stream.avail_out == 0) { + + CURR_VEC(ci).iov_len = ci->buffer_size; + + ret = cdc_alloc_iobuf_and_init_vec (this, priv, ci, 0); + if (ret) + break; + + /* Re-position Zlib output buffer */ + cdc_init_zlib_output_stream (priv, ci, 0); + } + + ret = deflate (&ci->stream, Z_NO_FLUSH); + if (ret != Z_OK) + break; + } + + out: + return ret; +} + +int32_t +cdc_compress (xlator_t *this, cdc_priv_t *priv, cdc_info_t *ci, + dict_t **xdata) +{ + int ret = -1; + int i = 0; + + ci->iobref = iobref_new (); + if (!ci->iobref) + goto out; + + if (!*xdata) { + *xdata = dict_new (); + if (!*xdata) { + gf_log (this->name, GF_LOG_ERROR, "Cannot allocate xdata" + " dict"); + goto out; + } + } + + /* data */ + for (i = 0; i < ci->count; i++) { + ret = do_cdc_compress (&ci->vector[i], this, priv, ci); + if (ret != Z_OK) + goto deflate_cleanup_out; + } + + /* flush zlib buffer */ + ret = cdc_flush_libz_buffer (priv, this, ci, deflate, Z_FINISH); + if (!(ret == Z_OK || ret == Z_STREAM_END)) { + gf_log (this->name, GF_LOG_ERROR, + "Compression Error: ret (%d)", ret); + ret = -1; + goto deflate_cleanup_out; + } + + /* trailer */ + ret = cdc_init_gzip_trailer (this, priv, ci); + if (ret) + goto deflate_cleanup_out; + + gf_log (this->name, GF_LOG_DEBUG, + "Compressed %ld to %ld bytes", + ci->stream.total_in, ci->stream.total_out); + + ci->nbytes = ci->stream.total_out + GF_CDC_VALIDATION_SIZE; + + /* set deflated canary value for identification */ + ret = dict_set_int32 (*xdata, GF_CDC_DEFLATE_CANARY_VAL, 1); + if (ret) { + /* Send uncompressed data if we can't _tell_ the client + * that deflated data is on it's way. So, we just log + * the faliure and continue as usual. + */ + gf_log (this->name, GF_LOG_ERROR, + "Data deflated, but could not set canary" + " value in dict for identification"); + } + + /* This is to be used in testing */ + if ( priv->debug ) { + cdc_dump_iovec_to_disk (this, ci, GF_CDC_DEBUG_DUMP_FILE ); + } + + deflate_cleanup_out: + (void) deflateEnd(&ci->stream); + + out: + return ret; +} + + +/* deflate content is checked by the presence of a canary + * value in the dict as the key + */ +static int32_t +cdc_check_content_for_deflate (dict_t *xdata) +{ + return dict_get (xdata, GF_CDC_DEFLATE_CANARY_VAL) ? -1 : 0; +} + +static unsigned long +cdc_extract_crc (char *trailer) +{ + return cdc_get_long ((unsigned char *) &trailer[0]); +} + +static unsigned long +cdc_extract_size (char *trailer) +{ + return cdc_get_long ((unsigned char *) &trailer[4]); +} + +static int32_t +cdc_validate_inflate (cdc_info_t *ci, unsigned long crc, + unsigned long len) +{ + return !((crc == ci->crc) + /* inflated length is hidden inside + * Zlib stream struct */ + && (len == ci->stream.total_out)); +} + +static int32_t +do_cdc_decompress (xlator_t *this, cdc_priv_t *priv, cdc_info_t *ci) +{ + int ret = -1; + int i = 0; + int len = 0; + char *inflte = NULL; + char *trailer = NULL; + struct iovec vec = {0,}; + unsigned long computed_crc = 0; + unsigned long computed_len = 0; + + ret = inflateInit2 (&ci->stream, priv->window_size); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Zlib: Unable to initialize inflate"); + goto out; + } + + vec = THIS_VEC(ci, 0); + + trailer = (char *) (((char *) vec.iov_base) + vec.iov_len + - GF_CDC_VALIDATION_SIZE); + + /* CRC of uncompressed data */ + computed_crc = cdc_extract_crc (trailer); + + /* size of uncomrpessed data */ + computed_len = cdc_extract_size (trailer); + + gf_log (this->name, GF_LOG_DEBUG, "crc=%lu len=%lu buffer_size=%d", + computed_crc, computed_len, ci->buffer_size); + + inflte = vec.iov_base ; + len = vec.iov_len - GF_CDC_VALIDATION_SIZE; + + /* allocate buffer of the original length of the data */ + ret = cdc_alloc_iobuf_and_init_vec (this, priv, ci, 0); + if (ret) + goto out; + + /* setup output buffer */ + cdc_init_zlib_output_stream (priv, ci, 0); + + /* setup input buffer */ + ci->stream.next_in = (unsigned char *) inflte; + ci->stream.avail_in = len; + + while (ci->stream.avail_in != 0) { + if (ci->stream.avail_out == 0) { + CURR_VEC(ci).iov_len = ci->buffer_size; + + ret = cdc_alloc_iobuf_and_init_vec (this, priv, ci, 0); + if (ret) + break; + + /* Re-position Zlib output buffer */ + cdc_init_zlib_output_stream (priv, ci, 0); + } + + ret = inflate (&ci->stream, Z_NO_FLUSH); + if (ret == Z_STREAM_ERROR) + break; + } + + /* flush zlib buffer */ + ret = cdc_flush_libz_buffer (priv, this, ci, inflate, Z_SYNC_FLUSH); + if (!(ret == Z_OK || ret == Z_STREAM_END)) { + gf_log (this->name, GF_LOG_ERROR, + "Decompression Error: ret (%d)", ret); + ret = -1; + goto out; + } + + /* compute CRC of the uncompresses data to check for + * correctness */ + + for (i = 0; i < ci->ncount; i++) { + ci->crc = crc32 (ci->crc, + (const Bytef *) ci->vec[i].iov_base, + ci->vec[i].iov_len); + } + + /* validate inflated data */ + ret = cdc_validate_inflate (ci, computed_crc, computed_len); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Checksum or length mismatched in inflated data"); + } + + out: + return ret; +} + +int32_t +cdc_decompress (xlator_t *this, cdc_priv_t *priv, cdc_info_t *ci, + dict_t *xdata) +{ + int32_t ret = -1; + + /* check for deflate content */ + if (!cdc_check_content_for_deflate (xdata)) { + gf_log (this->name, GF_LOG_DEBUG, + "Content not deflated, passing through ..."); + goto passthrough_out; + } + + ci->iobref = iobref_new (); + if (!ci->iobref) + goto passthrough_out; + + /* do we need to do this? can we assume that one iovec + * will hold per request data everytime? + * + * server/client protocol seems to deal with a single + * iovec even if op_ret > 1M. So, it looks ok to + * assume that a single iovec will contain all the + * data (This saves us a lot from finding the trailer + * and the data since it could have been split-up onto + * two adjacent iovec's. + * + * But, in case this translator is loaded above quick-read + * for some reason, then it's entirely possible that we get + * multiple iovec's... + * + * This case (handled below) is not tested. (by loading the + * xlator below quick-read) + */ + + /* @@ I_HOPE_THIS_IS_NEVER_HIT */ + if (ci->count > 1) { + gf_log (this->name, GF_LOG_WARNING, "unable to handle" + " multiple iovecs (%d in number)", ci->count); + goto inflate_cleanup_out; + /* TODO: coallate all iovecs in one */ + } + + ret = do_cdc_decompress (this, priv, ci); + if (ret) + goto inflate_cleanup_out; + + ci->nbytes = ci->stream.total_out; + + gf_log (this->name, GF_LOG_DEBUG, + "Inflated %ld to %ld bytes", + ci->stream.total_in, ci->stream.total_out); + + inflate_cleanup_out: + (void) inflateEnd (&ci->stream); + + passthrough_out: + return ret; +} + +#endif |