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 +++++++++++++++++++++++++++++++++++++++++++- src/journal/compress.h | 4 ++ src/journal/test-compress.c | 54 ++++++++++++++++ 3 files changed, 209 insertions(+), 3 deletions(-) (limited to 'src/journal') 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; + } + } + } +} diff --git a/src/journal/compress.h b/src/journal/compress.h index 2b87e73a26..f37a6b3d14 100644 --- a/src/journal/compress.h +++ b/src/journal/compress.h @@ -23,6 +23,7 @@ #include #include +#include bool compress_blob(const void *src, uint64_t src_size, void *dst, uint64_t *dst_size); @@ -33,3 +34,6 @@ bool uncompress_startswith(const void *src, uint64_t src_size, void **buffer, uint64_t *buffer_size, const void *prefix, uint64_t prefix_len, uint8_t extra); + +int compress_stream(int fdf, int fdt, off_t max_size); +int decompress_stream(int fdf, int fdt, off_t max_size); diff --git a/src/journal/test-compress.c b/src/journal/test-compress.c index 15b3f9aa00..b098ef93a8 100644 --- a/src/journal/test-compress.c +++ b/src/journal/test-compress.c @@ -68,9 +68,63 @@ static void test_uncompress_startswith(void) { "barbarbar", 9, ' ')); } +static void test_compress_stream(const char *srcfile) { + _cleanup_close_ int src = -1, dst = -1, dst2 = -1; + char pattern[] = "/tmp/systemd-test.xz.XXXXXX", + pattern2[] = "/tmp/systemd-test.xz.XXXXXX"; + int r; + _cleanup_free_ char *cmd, *cmd2; + struct stat st = {}; + + log_debug("/* create source from %s */", srcfile); + + assert_se((src = open(srcfile, O_RDONLY|O_CLOEXEC)) >= 0); + + log_debug("/* test compression */"); + + assert_se((dst = mkostemp_safe(pattern, O_RDWR|O_CLOEXEC)) >= 0); + + r = compress_stream(src, dst, -1); + assert(r == 0); + + assert_se(asprintf(&cmd, "xzcat %s | diff %s -", pattern, srcfile) > 0); + assert_se(system(cmd) == 0); + + log_debug("/* test decompression */"); + + assert_se((dst2 = mkostemp_safe(pattern2, O_RDWR|O_CLOEXEC)) >= 0); + + assert_se(stat(srcfile, &st) == 0); + + assert_se(lseek(dst, 0, SEEK_SET) == 0); + r = decompress_stream(dst, dst2, st.st_size); + assert(r == 0); + + assert_se(asprintf(&cmd2, "diff %s %s", srcfile, pattern2) > 0); + assert_se(system(cmd2) == 0); + + log_debug("/* test faulty decompression */"); + + assert_se(lseek(dst, 1, SEEK_SET) == 1); + r = decompress_stream(dst, dst2, st.st_size); + assert(r == -EBADMSG); + + assert_se(lseek(dst, 0, SEEK_SET) == 0); + assert_se(lseek(dst2, 0, SEEK_SET) == 0); + r = decompress_stream(dst, dst2, st.st_size - 1); + assert(r == -E2BIG); + + assert_se(unlink(pattern) == 0); + assert_se(unlink(pattern2) == 0); +} + int main(int argc, char *argv[]) { + + log_set_max_level(LOG_DEBUG); + test_compress_uncompress(); test_uncompress_startswith(); + test_compress_stream(argv[0]); return 0; } -- cgit v1.2.3-54-g00ecf