New compression APIs are added for writing and reading compressed data from / to files in chunks: tracecmd_compress_copy_from() tracecmd_uncompress_copy_to() Format of the compressed data, used by these APIs, is: - 4 bytes, chunks count - for each chunk: - 4 bytes, size of compressed data in this chunk - 4 bytes, uncompressed size of the data in this chunk - data, bytes of <size of compressed data in this chunk> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx> --- .../include/private/trace-cmd-private.h | 5 +- lib/trace-cmd/trace-compress.c | 200 ++++++++++++++++++ 2 files changed, 204 insertions(+), 1 deletion(-) diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h index 10089389..067ba34d 100644 --- a/lib/trace-cmd/include/private/trace-cmd-private.h +++ b/lib/trace-cmd/include/private/trace-cmd-private.h @@ -494,7 +494,10 @@ int tracecmd_compress_proto_register(const char *name, const char *version, int char *out, unsigned int *out_bytes), unsigned int (*comress_size)(unsigned int bytes), bool (*is_supported)(const char *name, const char *version)); - +int tracecmd_compress_copy_from(struct tracecmd_compression *handle, int fd, int chunk_size, + unsigned long long *read_size, unsigned long long *write_size); +int tracecmd_uncompress_copy_to(struct tracecmd_compression *handle, int fd, + unsigned long long *read_size, unsigned long long *write_size); /* --- Plugin handling --- */ extern struct tep_plugin_option trace_ftrace_options[]; diff --git a/lib/trace-cmd/trace-compress.c b/lib/trace-cmd/trace-compress.c index 2b329d00..4a4707c2 100644 --- a/lib/trace-cmd/trace-compress.c +++ b/lib/trace-cmd/trace-compress.c @@ -594,3 +594,203 @@ error: free(v); return -1; } + +/** + * tracecmd_compress_copy_from - Copy and compress data from a file + * @handle: compression handler + * @fd: file descriptor to uncompressed data + * @chunk_size: size of one compression chunk + * @read_size: in - max bytes to read from @fd, 0 to read till the EOF + * out - size of the uncompressed data read from @fd + * @write_size: return, size of the compressed data written into @handle + * + * This function reads uncompressed data from given @fd until EOF is reached, compresses + * the data using the @handle compression context and writes the compressed data into the fd + * associated with the @handle. The data is compressed on chunks with given @chunk_size size. + * The compressed data is written in the format: + * - 4 bytes, chunks count + * - for each chunk: + * - 4 bytes, size of compressed data in this chunk + * - 4 bytes, uncompressed size of the data in this chunk + * - data, bytes of <size of compressed data in this chunk> + * + * On success 0 is returned, @read_size and @write_size are updated with the size of + * read and written data. + */ +int tracecmd_compress_copy_from(struct tracecmd_compression *handle, int fd, int chunk_size, + unsigned long long *read_size, unsigned long long *write_size) +{ + unsigned int chunks = 0; + unsigned int rsize = 0; + unsigned int rmax = 0; + unsigned int wsize = 0; + unsigned int csize; + unsigned int rchunk = 0; + unsigned int size; + unsigned int r; + off64_t offset; + char *buf_from; + char *buf_to; + int endian4; + int ret; + + if (!handle || !handle->proto || + !handle->proto->comress_block || !handle->proto->comress_size) + return 0; + if (read_size) + rmax = *read_size; + csize = handle->proto->comress_size(chunk_size); + buf_from = malloc(chunk_size); + if (!buf_from) + return -1; + buf_to = malloc(csize); + if (!buf_to) + return -1; + /* save the initial offset and write 0 chunks */ + offset = lseek64(handle->fd, 0, SEEK_CUR); + write_fd(handle->fd, &chunks, 4); + + do { + if (rmax > 0 && (rmax - rsize) < chunk_size) + rchunk = (rmax - rsize); + else + rchunk = chunk_size; + + r = read(fd, buf_from, rchunk); + if (r < 0 || (rmax > 0 && rsize >= rmax)) + break; + rsize += r; + size = csize; + if (r > 0) { + ret = handle->proto->comress_block(buf_from, r, buf_to, &size); + if (ret < 0) { + if (errno == EINTR) + continue; + break; + } + /* Write compressed data size */ + endian4 = tep_read_number(handle->tep, &size, 4); + ret = write_fd(handle->fd, &endian4, 4); + if (ret != 4) + break; + /* Write uncompressed data size */ + endian4 = tep_read_number(handle->tep, &r, 4); + ret = write_fd(handle->fd, &endian4, 4); + if (ret != 4) + break; + /* Write the compressed data */ + ret = write_fd(handle->fd, buf_to, size); + if (ret != size) + break; + /* data + compress header */ + wsize += (size + 8); + chunks++; + } + } while (r > 0); + free(buf_from); + free(buf_to); + if (r) + return -1; + if (lseek64(handle->fd, offset, SEEK_SET) == (off_t)-1) + return -1; + endian4 = tep_read_number(handle->tep, &chunks, 4); + /* write chunks count*/ + write_fd(handle->fd, &chunks, 4); + lseek64(handle->fd, offset, SEEK_SET); + if (lseek64(handle->fd, 0, SEEK_END) == (off_t)-1) + return -1; + if (read_size) + *read_size = rsize; + if (write_size) + *write_size = wsize; + return 0; +} + +/** + * tracecmd_uncompress_copy_to - Uncompress data and copy to a file + * @handle: compression handler + * @fd: file descriptor to uncompressed data + * @read_size: return, size of the compressed data read from @handle + * @write_size: return, size of the uncompressed data written into @fd + * + * This function reads compressed data from the fd, associated with @handle, uncompresses it + * using the @handle compression context and writes the uncompressed data into the fd. + * The compressed data must be in the format: + * - 4 bytes, chunks count + * - for each chunk: + * - 4 bytes, size of compressed data in this chunk + * - 4 bytes, uncompressed size of the data in this chunk + * - data, bytes of <size of compressed data in this chunk> + * + * On success 0 is returned, @read_size and @write_size are updated with the size of + * read and written data. + */ +int tracecmd_uncompress_copy_to(struct tracecmd_compression *handle, int fd, + unsigned long long *read_size, unsigned long long *write_size) +{ + unsigned int s_uncompressed; + unsigned int s_compressed; + unsigned int rsize = 0; + unsigned int wsize = 0; + char *bytes_out = NULL; + char *bytes_in = NULL; + int size_out; + int size_in; + int chunks; + char buf[4]; + char *tmp; + int ret; + + if (!handle || !handle->proto || !handle->proto->uncompress_block) + return -1; + + if (read(handle->fd, buf, 4) != 4) + return -1; + chunks = tep_read_number(handle->tep, buf, 4); + rsize += 4; + while (chunks) { + if (read(handle->fd, buf, 4) != 4) + break; + s_compressed = tep_read_number(handle->tep, buf, 4); + rsize += 4; + if (read(handle->fd, buf, 4) != 4) + break; + s_uncompressed = tep_read_number(handle->tep, buf, 4); + rsize += 4; + if (!bytes_in || size_in < s_compressed) { + tmp = realloc(bytes_in, s_compressed); + if (!tmp) + break; + bytes_in = tmp; + size_in = s_compressed; + } + + if (!bytes_out || size_out < s_uncompressed) { + tmp = realloc(bytes_out, s_uncompressed); + if (!tmp) + break; + bytes_out = tmp; + size_out = s_uncompressed; + } + + if (read_fd(handle->fd, bytes_in, s_compressed) < 0) + break; + rsize += s_compressed; + ret = handle->proto->uncompress_block(bytes_in, s_compressed, + bytes_out, &s_uncompressed); + if (ret) + break; + write_fd(fd, bytes_out, s_uncompressed); + wsize += s_uncompressed; + chunks--; + } + free(bytes_in); + free(bytes_out); + if (chunks) + return -1; + if (read_size) + *read_size = rsize; + if (write_size) + *write_size = wsize; + return 0; +} -- 2.31.1