From 355b59e252c9910e44a1ad95c045ba8db58a4f6a Mon Sep 17 00:00:00 2001 From: Zbigniew Jędrzejewski-Szmek Date: Tue, 24 Jun 2014 21:24:46 -0400 Subject: journal/compress: add stream compression/decompression functions --- src/journal/compress.c | 154 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 151 insertions(+), 3 deletions(-) (limited to 'src/journal/compress.c') diff --git a/src/journal/compress.c b/src/journal/compress.c index cafe8f4f54..f36c430801 100644 --- a/src/journal/compress.c +++ b/src/journal/compress.c @@ -22,10 +22,12 @@ #include #include #include +#include #include -#include "macro.h" #include "compress.h" +#include "macro.h" +#include "util.h" bool compress_blob(const void *src, uint64_t src_size, void *dst, uint64_t *dst_size) { lzma_ret ret; @@ -40,12 +42,12 @@ bool compress_blob(const void *src, uint64_t src_size, void *dst, uint64_t *dst_ * compressed result is longer than the original */ ret = lzma_easy_buffer_encode(LZMA_PRESET_DEFAULT, LZMA_CHECK_NONE, NULL, - src, src_size, dst, &out_pos, *dst_size); + src, src_size, dst, &out_pos, src_size); if (ret != LZMA_OK) return false; /* Is it actually shorter? */ - if (out_pos == *dst_size) + if (out_pos == src_size) return false; *dst_size = out_pos; @@ -200,3 +202,149 @@ fail: return b; } + +int compress_stream(int fdf, int fdt, off_t max_bytes) { + _cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT; + lzma_ret ret; + + uint8_t buf[BUFSIZ], out[BUFSIZ]; + lzma_action action = LZMA_RUN; + + assert(fdf >= 0); + assert(fdt >= 0); + + ret = lzma_easy_encoder(&s, LZMA_PRESET_DEFAULT, LZMA_CHECK_CRC64); + if (ret != LZMA_OK) { + log_error("Failed to initialize XZ encoder: code %d", ret); + return -EINVAL; + } + + for (;;) { + if (s.avail_in == 0 && action == LZMA_RUN) { + size_t m = sizeof(buf); + ssize_t n; + + if (max_bytes != -1 && m > (size_t) max_bytes) + m = max_bytes; + + n = read(fdf, buf, m); + if (n < 0) + return -errno; + if (n == 0) + action = LZMA_FINISH; + else { + s.next_in = buf; + s.avail_in = n; + + if (max_bytes != -1) { + assert(max_bytes >= n); + max_bytes -= n; + } + } + } + + if (s.avail_out == 0) { + s.next_out = out; + s.avail_out = sizeof(out); + } + + ret = lzma_code(&s, action); + if (ret != LZMA_OK && ret != LZMA_STREAM_END) { + log_error("Compression failed: code %d", ret); + return -EBADMSG; + } + + if (s.avail_out == 0 || ret == LZMA_STREAM_END) { + ssize_t n, k; + + n = sizeof(out) - s.avail_out; + + errno = 0; + k = loop_write(fdt, out, n, false); + if (k < 0) + return k; + if (k != n) + return errno ? -errno : -EIO; + + if (ret == LZMA_STREAM_END) { + log_debug("Compression finished (%zu -> %zu bytes, %.1f%%)", + s.total_in, s.total_out, + (double) s.total_out / s.total_in * 100); + + return 0; + } + } + } +} + +int decompress_stream(int fdf, int fdt, off_t max_bytes) { + _cleanup_(lzma_end) lzma_stream s = LZMA_STREAM_INIT; + lzma_ret ret; + + uint8_t buf[BUFSIZ], out[BUFSIZ]; + lzma_action action = LZMA_RUN; + + assert(fdf >= 0); + assert(fdt >= 0); + + ret = lzma_stream_decoder(&s, UINT64_MAX, 0); + if (ret != LZMA_OK) { + log_error("Failed to initialize XZ decoder: code %d", ret); + return -EINVAL; + } + + for (;;) { + if (s.avail_in == 0 && action == LZMA_RUN) { + ssize_t n; + + n = read(fdf, buf, sizeof(buf)); + if (n < 0) + return -errno; + if (n == 0) + action = LZMA_FINISH; + else { + s.next_in = buf; + s.avail_in = n; + } + } + + if (s.avail_out == 0) { + s.next_out = out; + s.avail_out = sizeof(out); + } + + ret = lzma_code(&s, action); + if (ret != LZMA_OK && ret != LZMA_STREAM_END) { + log_error("Decompression failed: code %d", ret); + return -EBADMSG; + } + + if (s.avail_out == 0 || ret == LZMA_STREAM_END) { + ssize_t n, k; + + n = sizeof(out) - s.avail_out; + + if (max_bytes != -1) { + if (max_bytes < n) + return -E2BIG; + + max_bytes -= n; + } + + errno = 0; + k = loop_write(fdt, out, n, false); + if (k < 0) + return k; + if (k != n) + return errno ? -errno : -EIO; + + if (ret == LZMA_STREAM_END) { + log_debug("Decompression finished (%zu -> %zu bytes, %.1f%%)", + s.total_in, s.total_out, + (double) s.total_out / s.total_in * 100); + + return 0; + } + } + } +} -- cgit v1.2.3-54-g00ecf