#include <stdint.h>
#include <glib.h>
+#include <string.h>
#include "bluesky.h"
return (int64_t)t.tv_sec * 1000000 + t.tv_usec;
}
+/* Update an inode to indicate that a modification was made. This increases
+ * the change counter, updates the ctime to the current time, and optionally
+ * updates the mtime. */
+void bluesky_inode_update_ctime(BlueSkyInode *inode, gboolean update_mtime)
+{
+ int64_t now = bluesky_get_current_time();
+ inode->change_count++;
+ inode->ctime = now;
+ if (update_mtime)
+ 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) {
case BLUESKY_REGULAR:
+ i->blocks = g_array_new(FALSE, TRUE, sizeof(BlueSkyBlock));
break;
case BLUESKY_DIRECTORY:
i->dirents = g_sequence_new(bluesky_dirent_destroy);
+ i->dirhash = g_hash_table_new(g_str_hash, g_str_equal);
+ break;
case BLUESKY_BLOCK:
case BLUESKY_CHARACTER:
case BLUESKY_SYMLINK:
g_hash_table_insert(fs->inodes, &inode->inum, inode);
g_mutex_unlock(fs->lock);
}
+
+/* Mark a given block dirty and make sure that data is faulted in so that it
+ * can be written to. */
+void bluesky_block_touch(BlueSkyInode *inode, uint64_t i)
+{
+ g_return_if_fail(i < inode->blocks->len);
+ BlueSkyBlock *block = &g_array_index(inode->blocks, BlueSkyBlock, i);
+
+ switch (block->type) {
+ case BLUESKY_BLOCK_ZERO:
+ block->data = bluesky_string_new(g_malloc0(BLUESKY_BLOCK_SIZE),
+ BLUESKY_BLOCK_SIZE);
+ break;
+ case BLUESKY_BLOCK_REF:
+ bluesky_block_fetch(inode->fs, block);
+ g_assert(block->type == BLUESKY_BLOCK_CACHED);
+ /* Fall through */
+ case BLUESKY_BLOCK_CACHED:
+ case BLUESKY_BLOCK_DIRTY:
+ block->data = bluesky_string_dup(block->data);
+ break;
+ }
+
+ block->type = BLUESKY_BLOCK_DIRTY;
+}
+
+/* Set the size of a file. This will truncate or extend the file as needed.
+ * Newly-allocated bytes are zeroed. */
+void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size)
+{
+ g_return_if_fail(size <= BLUESKY_MAX_FILE_SIZE);
+
+ if (size == inode->size)
+ return;
+
+ uint64_t blocks = (size + BLUESKY_BLOCK_SIZE - 1) / BLUESKY_BLOCK_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. */
+ g_array_set_size(inode->blocks, blocks);
+ } else if (blocks < inode->blocks->len) {
+ /* Delete blocks from a file. Must reclaim memory. */
+ for (guint i = inode->blocks->len; i < blocks; i++) {
+ BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, i);
+ g_free(b->ref);
+ bluesky_string_unref(b->data);
+ }
+ g_array_set_size(inode->blocks, blocks);
+ }
+
+ /* If the file size is being decreased, ensure that any trailing data in
+ * the last block is zeroed. */
+ if (size < inode->size) {
+ BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
+ blocks - 1);
+ if (b->type != BLUESKY_BLOCK_ZERO) {
+ bluesky_block_touch(inode, blocks - 1);
+ int end_offset = size % BLUESKY_BLOCK_SIZE;
+ if (end_offset > 0) {
+ memset(&b->data->data[end_offset], 0,
+ BLUESKY_BLOCK_SIZE - end_offset);
+ }
+ }
+ }
+
+ inode->size = size;
+ bluesky_inode_update_ctime(inode, 1);
+}
+
+void bluesky_file_write(BlueSkyInode *inode, uint64_t offset,
+ const char *data, gint len)
+{
+ g_return_if_fail(inode->type == BLUESKY_REGULAR);
+ g_return_if_fail(offset < inode->size);
+ g_return_if_fail(len <= inode->size - offset);
+
+ if (len == 0)
+ return;
+
+ while (len > 0) {
+ uint64_t block_num = offset / BLUESKY_BLOCK_SIZE;
+ gint block_offset = offset % BLUESKY_BLOCK_SIZE;
+ gint bytes = MIN(BLUESKY_BLOCK_SIZE - block_offset, len);
+
+ bluesky_block_touch(inode, block_num);
+ BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
+ block_num);
+ memcpy(&b->data->data[block_offset], data, bytes);
+ bluesky_block_flush(inode->fs, b);
+
+ offset += bytes;
+ data += bytes;
+ len -= bytes;
+ }
+
+ bluesky_inode_update_ctime(inode, 1);
+}
+
+void bluesky_file_read(BlueSkyInode *inode, uint64_t offset,
+ char *buf, gint len)
+{
+ g_return_if_fail(inode->type == BLUESKY_REGULAR);
+ g_return_if_fail(offset < inode->size);
+ g_return_if_fail(len <= inode->size - offset);
+
+ while (len > 0) {
+ uint64_t block_num = offset / BLUESKY_BLOCK_SIZE;
+ gint block_offset = offset % BLUESKY_BLOCK_SIZE;
+ gint bytes = MIN(BLUESKY_BLOCK_SIZE - block_offset, len);
+
+ BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock,
+ block_num);
+ switch (b->type) {
+ case BLUESKY_BLOCK_ZERO:
+ memset(buf, 0, bytes);
+ break;
+ case BLUESKY_BLOCK_REF:
+ bluesky_block_fetch(inode->fs, b);
+ /* Fall through */
+ case BLUESKY_BLOCK_CACHED:
+ case BLUESKY_BLOCK_DIRTY:
+ memcpy(buf, &b->data->data[block_offset], bytes);
+ break;
+ }
+
+ offset += bytes;
+ buf += 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);
+
+ bluesky_string_unref(block->data);
+ block->data = string;
+ block->type = BLUESKY_BLOCK_CACHED;
+}
+
+/* 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;
+
+ GChecksum *csum = g_checksum_new(G_CHECKSUM_SHA256);
+ g_checksum_update(csum, block->data->data, block->data->len);
+ gchar *name = g_strdup(g_checksum_get_string(csum));
+
+ g_print("Flushing block as %s\n", name);
+ s3store_put(fs->store, name, block->data);
+ g_free(block->ref);
+ block->ref = name;
+
+ /* block->type = BLUESKY_BLOCK_CACHED; */
+ bluesky_string_unref(block->data);
+ block->data = NULL;
+ block->type = BLUESKY_BLOCK_REF;
+
+ g_checksum_free(csum);
+}
projects / bluesky.git / blobdiff