inode->mtime = now;
}
+/* Compute the HMAC keyed-hash function using the given hash algorithm, data,
+ * and key. */
+void compute_hmac(GChecksumType algo,
+ const guchar *data, gsize data_len,
+ const guchar *key, gsize key_len,
+ guint8 *buffer, gsize *digest_len)
+{
+ int block_size;
+
+ switch (algo) {
+ case G_CHECKSUM_MD5:
+ case G_CHECKSUM_SHA1:
+ case G_CHECKSUM_SHA256:
+ block_size = 64;
+ break;
+ default:
+ g_error("Unknown hash algorithm for HMAC: %d\n", algo);
+ }
+
+ gsize digest_size = g_checksum_type_get_length(algo);
+
+ guchar keybuf[block_size];
+ memset(keybuf, 0, block_size);
+ memcpy(keybuf, key, MIN(block_size, key_len));
+ for (int i = 0; i < block_size; i++)
+ keybuf[i] ^= 0x36;
+
+ GChecksum *csum1 = g_checksum_new(algo);
+ g_checksum_update(csum1, keybuf, block_size);
+ g_checksum_update(csum1, data, data_len);
+ guint8 digest[digest_size];
+ g_checksum_get_digest(csum1, digest, &digest_size);
+
+ memset(keybuf, 0, block_size);
+ memcpy(keybuf, key, MIN(block_size, key_len));
+ for (int i = 0; i < block_size; i++)
+ keybuf[i] ^= 0x5c;
+
+ GChecksum *csum2 = g_checksum_new(algo);
+ g_checksum_update(csum2, keybuf, block_size);
+ g_checksum_update(csum2, digest, digest_size);
+
+ g_checksum_get_digest(csum2, buffer, digest_len);
+
+ g_checksum_free(csum1);
+ g_checksum_free(csum2);
+}
+
/* Unfortunately a glib hash table is only guaranteed to be able to store
* 32-bit keys if we use the key directly. If we want 64-bit inode numbers,
* we'll have to allocate memory to store the 64-bit inumber, and use a pointer
fs->inodes = g_hash_table_new(bluesky_fs_key_hash_func,
bluesky_fs_key_equal_func);
fs->next_inum = BLUESKY_ROOT_INUM + 1;
+ fs->store = s3store_new();
return fs;
}
return inum;
}
-BlueSkyInode *bluesky_new_inode(uint64_t inum, BlueSkyFileType type)
+BlueSkyInode *bluesky_new_inode(uint64_t inum, BlueSkyFS *fs,
+ BlueSkyFileType type)
{
BlueSkyInode *i = g_new0(BlueSkyInode, 1);
i->lock = g_mutex_new();
i->type = type;
+ i->fs = fs;
i->inum = inum;
switch (type) {
BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
block_num);
memcpy(&b->data[block_offset], data, bytes);
+ bluesky_block_flush(inode->fs, b);
offset += bytes;
data += bytes;
memset(buf, 0, bytes);
break;
case BLUESKY_BLOCK_REF:
- /* TODO: Pull in data first */
- memset(buf, 0, bytes);
- break;
+ bluesky_block_fetch(inode->fs, b);
+ /* Fall through */
case BLUESKY_BLOCK_CACHED:
case BLUESKY_BLOCK_DIRTY:
memcpy(buf, &b->data[block_offset], bytes);
len -= bytes;
}
}
+
+/* Read the given block from cloud-backed storage if the data is not already
+ * cached. */
+void bluesky_block_fetch(BlueSkyFS *fs, BlueSkyBlock *block)
+{
+ if (block->type != BLUESKY_BLOCK_REF)
+ return;
+
+ g_print("Fetching block from %s\n", block->ref);
+ BlueSkyRCStr *string = s3store_get(fs->store, block->ref);
+
+ g_free(block->data);
+ block->data = g_memdup(string->data, BLUESKY_BLOCK_SIZE);
+ block->type = BLUESKY_BLOCK_CACHED;
+ bluesky_string_unref(string);
+}
+
+/* Write the given block to cloud-backed storage and mark it clean. */
+void bluesky_block_flush(BlueSkyFS *fs, BlueSkyBlock *block)
+{
+ if (block->type != BLUESKY_BLOCK_DIRTY)
+ return;
+
+ BlueSkyRCStr *data = bluesky_string_new(g_memdup(block->data,
+ BLUESKY_BLOCK_SIZE),
+ BLUESKY_BLOCK_SIZE);
+
+ GChecksum *csum = g_checksum_new(G_CHECKSUM_SHA256);
+ g_checksum_update(csum, data->data, data->len);
+ const gchar *name = g_checksum_get_string(csum);
+
+ g_print("Flushing block as %s\n", name);
+ s3store_put(fs->store, name, data);
+ g_free(block->ref);
+ block->ref = g_strdup(name);
+
+ /* block->type = BLUESKY_BLOCK_CACHED; */
+ g_free(block->data);
+ block->data = NULL;
+ block->type = BLUESKY_BLOCK_REF;
+
+ g_checksum_free(csum);
+ bluesky_string_unref(data);
+}