journal/compress: simplify compress_blob

[elogind.git] / src / journal / compress.c

diff --git a/src/journal/compress.c b/src/journal/compress.c
index 75e70c5ffa8b8d60b0aaca7eb00a0670d0435a85..cafe8f4f54e4758993a9531d746d04613d25e44c 100644 (file)
--- a/src/journal/compress.c
+++ b/src/journal/compress.c
@@ -24,12 +24,12 @@
 #include <string.h>
 #include <lzma.h>
 
+#include "macro.h"
 #include "compress.h"
 
 bool compress_blob(const void *src, uint64_t src_size, void *dst, uint64_t *dst_size) {
-        lzma_stream s = LZMA_STREAM_INIT;
         lzma_ret ret;
-        bool b = false;
+        size_t out_pos = 0;
 
         assert(src);
         assert(src_size > 0);
@@ -39,37 +39,25 @@ bool compress_blob(const void *src, uint64_t src_size, void *dst, uint64_t *dst_
         /* Returns false if we couldn't compress the data or the
          * compressed result is longer than the original */
 
-        ret = lzma_easy_encoder(&s, LZMA_PRESET_DEFAULT, LZMA_CHECK_NONE);
+        ret = lzma_easy_buffer_encode(LZMA_PRESET_DEFAULT, LZMA_CHECK_NONE, NULL,
+                                      src, src_size, dst, &out_pos, *dst_size);
         if (ret != LZMA_OK)
                 return false;
 
-        s.next_in = src;
-        s.avail_in = src_size;
-        s.next_out = dst;
-        s.avail_out = src_size;
-
-        /* Does it fit? */
-        if (lzma_code(&s, LZMA_FINISH) != LZMA_STREAM_END)
-                goto fail;
-
         /* Is it actually shorter? */
-        if (s.avail_out == 0)
-                goto fail;
-
-        *dst_size = src_size - s.avail_out;
-        b = true;
-
-fail:
-        lzma_end(&s);
+        if (out_pos == *dst_size)
+                return false;
 
-        return b;
+        *dst_size = out_pos;
+        return true;
 }
 
 bool uncompress_blob(const void *src, uint64_t src_size,
-                     void **dst, uint64_t *dst_alloc_size, uint64_t* dst_size) {
+                     void **dst, uint64_t *dst_alloc_size, uint64_t* dst_size, uint64_t dst_max) {
 
         lzma_stream s = LZMA_STREAM_INIT;
         lzma_ret ret;
+        uint64_t space;
         bool b = false;
 
         assert(src);
@@ -98,7 +86,8 @@ bool uncompress_blob(const void *src, uint64_t src_size,
         s.avail_in = src_size;
 
         s.next_out = *dst;
-        s.avail_out = *dst_alloc_size;
+        space = dst_max > 0 ? MIN(*dst_alloc_size, dst_max) : *dst_alloc_size;
+        s.avail_out = space;
 
         for (;;) {
                 void *p;
@@ -111,18 +100,23 @@ bool uncompress_blob(const void *src, uint64_t src_size,
                 if (ret != LZMA_OK)
                         goto fail;
 
-                p = realloc(*dst, *dst_alloc_size*2);
+                if (dst_max > 0 && (space - s.avail_out) >= dst_max)
+                        break;
+
+                p = realloc(*dst, space*2);
                 if (!p)
                         goto fail;
 
                 s.next_out = (uint8_t*) p + ((uint8_t*) s.next_out - (uint8_t*) *dst);
-                s.avail_out += *dst_alloc_size;
+                s.avail_out += space;
+
+                space *= 2;
 
                 *dst = p;
-                *dst_alloc_size *= 2;
+                *dst_alloc_size = space;
         }
 
-        *dst_size = *dst_alloc_size - s.avail_out;
+        *dst_size = space - s.avail_out;
         b = true;
 
 fail: