Add very rudimentary eviction data blocks from the cache.

[bluesky.git] / bluesky / file.c

diff --git a/bluesky/file.c b/bluesky/file.c
index 3be40f0..2df979e 100644 (file)
--- a/bluesky/file.c
+++ b/bluesky/file.c
@@ -63,7 +63,24 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size)
     if (blocks > inode->blocks->len) {
         /* Need to add new blocks to the end of a file.  New block structures
          * are automatically zeroed, which initializes them to be pointers to
-         * zero blocks so we don't need to do any more work. */
+         * zero blocks so we don't need to do any more work.  If the
+         * previously-last block in the file is smaller than
+         * BLUESKY_BLOCK_SIZE, extend it to full size. */
+        if (inode->blocks->len > 0) {
+            BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
+                                             inode->blocks->len - 1);
+
+            if (b->type != BLUESKY_BLOCK_ZERO
+                    && (b->type == BLUESKY_BLOCK_REF
+                        || b->data->len < BLUESKY_BLOCK_SIZE)) {
+                bluesky_block_touch(inode, inode->blocks->len - 1);
+                gsize old_size = b->data->len;
+                bluesky_string_resize(b->data, BLUESKY_BLOCK_SIZE);
+                memset(&b->data->data[old_size], 0,
+                       BLUESKY_BLOCK_SIZE - old_size);
+            }
+        }
+
         g_array_set_size(inode->blocks, blocks);
     } else if (blocks < inode->blocks->len) {
         /* Delete blocks from a file.  Must reclaim memory. */
@@ -75,8 +92,8 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size)
         g_array_set_size(inode->blocks, blocks);
     }
 
-    /* Ensure the last block of the file is properly sized.  If the block is
-     * extended, newly-added bytes must be zeroed. */
+    /* Ensure the new last block of the file is properly sized.  If the block
+     * is extended, newly-added bytes must be zeroed. */
     if (blocks > 0) {
         BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
                                          blocks - 1);
@@ -190,7 +207,7 @@ void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block,
     BlueSkyRCStr *data = block->data;
 
     GChecksum *csum = g_checksum_new(G_CHECKSUM_SHA256);
-    g_checksum_update(csum, data->data, data->len);
+    g_checksum_update(csum, (const guchar *)data->data, data->len);
     gchar *name = g_strdup(g_checksum_get_string(csum));
 
     /* Store the file data asynchronously, and don't bother waiting for a
@@ -227,3 +244,22 @@ void bluesky_file_flush(BlueSkyInode *inode, BlueSkyStoreAsync *barrier)
         bluesky_block_flush(inode->fs, b, barrier);
     }
 }
+
+/* Drop clean data blocks for a file from cache. */
+void bluesky_file_drop_cached(BlueSkyInode *inode)
+{
+    g_return_if_fail(inode->type == BLUESKY_REGULAR);
+
+    for (int i = 0; i < inode->blocks->len; i++) {
+        BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
+        if (b->type == BLUESKY_BLOCK_CACHED) {
+            g_log("bluesky/cache", G_LOG_LEVEL_DEBUG,
+                  "Dropping block %d of inode %"PRIu64" from cache",
+                  i, inode->inum);
+
+            bluesky_string_unref(b->data);
+            b->data = NULL;
+            b->type = BLUESKY_BLOCK_REF;
+        }
+    }
+}