Data_read() no longer gives warning messages when reaching the end of…

… the cache file.

.gitignore

@@ -1,5 +1,3 @@
 *.o
 *.kate-swp
-html
-mnt
 httpdirfs

CHANGELOG.md

@@ -26,10 +26,12 @@ opened.
  - This problem only occurred during the first time you download a file.
  During subsequent accesses, when you are only reading from the cache, this
  problem did not occur.
-- Cache system: Previously it was possible for cache_bgdl()'s download offset
+- Cache system: Previously it was possible for Cache_bgdl()'s download offset
  to be modified by the parent thread after the child thread had been
  launched. This used to cause permanent cache file corruption.
-- Cache system: cache_bgdl() no longer prefetches beyond EOF.
+- Cache system: Cache_bgdl() no longer prefetches beyond EOF.
+- Cache system: Data_read() no longer gives warning messages when reaching the
+end of the cache file.
 
 ## [1.1.8] - 2019-08-24
 ### Changed

src/cache.c

@@ -360,20 +360,23 @@ static long Data_read(Cache *cf, uint8_t *buf, off_t len, off_t offset)
  #endif
  PTHREAD_MUTEX_LOCK(&cf->seek_lock);
 
+ long byte_read = 0;
+
  if (fseeko(cf->dfp, offset, SEEK_SET)) {
  /* fseeko failed */
  fprintf(stderr, "Data_read(): fseeko(): %s\n", strerror(errno));
+ byte_read = -EIO;
+ goto end;
+ }
 
- #ifdef CACHE_LOCK_DEBUG
- fprintf(stderr, "Data_read(): thread %lu: unlocking seek_lock;\n",
- pthread_self());
- #endif
- PTHREAD_MUTEX_UNLOCK(&cf->seek_lock);
-
- return -EIO;
+ if (offset + len > cf->content_length) {
+ len -= offset + len - cf->content_length;
+ if (len < 0) {
+ goto end;
+ }
  }
 
- long byte_read = fread(buf, sizeof(uint8_t), len, cf->dfp);
+ byte_read = fread(buf, sizeof(uint8_t), len, cf->dfp);
  if (byte_read != len) {
  fprintf(stderr,
  "Data_read(): fread(): requested %ld, returned %ld!\n",
@@ -390,6 +393,7 @@ static long Data_read(Cache *cf, uint8_t *buf, off_t len, off_t offset)
  }
  }
 
+ end:
  #ifdef CACHE_LOCK_DEBUG
  fprintf(stderr, "Data_read(): thread %lu: unlocking seek_lock;\n",
  pthread_self());
@@ -424,19 +428,16 @@ static long Data_write(Cache *cf, const uint8_t *buf, off_t len,
  #endif
  PTHREAD_MUTEX_LOCK(&cf->seek_lock);
 
+ long byte_written = 0;
+
  if (fseeko(cf->dfp, offset, SEEK_SET)) {
  /* fseeko failed */
  fprintf(stderr, "Data_write(): fseeko(): %s\n", strerror(errno));
-
- #ifdef CACHE_LOCK_DEBUG
- fprintf(stderr, "Data_write(): thread %lu: unlocking seek_lock;\n",
- pthread_self());
- #endif
- PTHREAD_MUTEX_UNLOCK(&cf->seek_lock);
- return -EIO;
+ byte_written = -EIO;
+ goto end;
  }
 
- long byte_written = fwrite(buf, sizeof(uint8_t), len, cf->dfp);
+ byte_written = fwrite(buf, sizeof(uint8_t), len, cf->dfp);
  if (byte_written != len) {
  fprintf(stderr,
  "Data_write(): fwrite(): requested %ld, returned %ld!\n",
@@ -448,6 +449,7 @@ static long Data_write(Cache *cf, const uint8_t *buf, off_t len,
  }
  }
 
+ end:
  #ifdef CACHE_LOCK_DEBUG
  fprintf(stderr, "Data_write(): thread %lu: unlocking seek_lock;\n",
  pthread_self());