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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-09-28 17:38:44 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2019-09-28 20:27:19 +0200
commit0bd27cbaec56d71b2525c2b37ae209396c65d45b (patch)
treec49b1826647d752d9d1572d71dd28da39312dc5c /lib/sqfs/xattr_writer.c
parent533c9b9d2b19639beda404d84b613bb2719e768f (diff)
Add recoding implementation for the xattr writer
This commit implements the part of the API responsible for recoding and deduplicating xattr key-value blocks. Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/sqfs/xattr_writer.c')
-rw-r--r--lib/sqfs/xattr_writer.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/lib/sqfs/xattr_writer.c b/lib/sqfs/xattr_writer.c
new file mode 100644
index 0000000..7643d49
--- /dev/null
+++ b/lib/sqfs/xattr_writer.c
@@ -0,0 +1,301 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * xattr_writer.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "config.h"
+
+#include "sqfs/xattr_writer.h"
+#include "sqfs/meta_writer.h"
+#include "sqfs/super.h"
+#include "sqfs/xattr.h"
+#include "sqfs/error.h"
+#include "sqfs/block.h"
+#include "sqfs/io.h"
+
+#include "str_table.h"
+#include "util.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+
+#define XATTR_KEY_BUCKETS 31
+#define XATTR_VALUE_BUCKETS 511
+#define XATTR_INITIAL_PAIR_CAP 128
+
+#define MK_PAIR(key, value) (((sqfs_u64)(key) << 32UL) | (sqfs_u64)(value))
+#define GET_KEY(pair) ((pair >> 32UL) & 0x0FFFFFFFFUL)
+#define GET_VALUE(pair) (pair & 0x0FFFFFFFFUL)
+
+
+static const char *hexmap = "0123456789ABCDEF";
+
+static char *to_base32(const void *input, size_t size)
+{
+ const uint8_t *in = input;
+ char *out, *ptr;
+ size_t i;
+
+ out = malloc(2 * size + 1);
+ if (out == NULL)
+ return NULL;
+
+ ptr = out;
+
+ for (i = 0; i < size; ++i) {
+ *(ptr++) = hexmap[ in[i] & 0x0F];
+ *(ptr++) = hexmap[(in[i] >> 4) & 0x0F];
+ }
+
+ *ptr = '\0';
+ return out;
+}
+
+static void *from_base32(const char *input, size_t *size_out)
+{
+ uint8_t lo, hi, *out, *ptr;
+ size_t len;
+
+ len = strlen(input);
+ *size_out = len / 2;
+
+ out = malloc(*size_out);
+ if (out == NULL)
+ return NULL;
+
+ ptr = out;
+
+ while (*input != '\0') {
+ lo = strchr(hexmap, *(input++)) - hexmap;
+ hi = strchr(hexmap, *(input++)) - hexmap;
+
+ *(ptr++) = lo | (hi << 4);
+ }
+
+ return out;
+}
+
+static int compare_u64(const void *a, const void *b)
+{
+ sqfs_u64 lhs = *((const sqfs_u64 *)a);
+ sqfs_u64 rhs = *((const sqfs_u64 *)b);
+
+ return (lhs < rhs ? -1 : (lhs > rhs ? 1 : 0));
+}
+
+
+
+typedef struct kv_block_desc_t {
+ struct kv_block_desc_t *next;
+ size_t start;
+ size_t count;
+} kv_block_desc_t;
+
+struct sqfs_xattr_writer_t {
+ str_table_t keys;
+ str_table_t values;
+
+ sqfs_u64 *kv_pairs;
+ size_t max_pairs;
+ size_t num_pairs;
+
+ size_t kv_start;
+
+ kv_block_desc_t *kv_blocks;
+ size_t num_blocks;
+};
+
+
+sqfs_xattr_writer_t *sqfs_xattr_writer_create(void)
+{
+ sqfs_xattr_writer_t *xwr = calloc(1, sizeof(*xwr));
+
+ if (str_table_init(&xwr->keys, XATTR_KEY_BUCKETS))
+ goto fail_keys;
+
+ if (str_table_init(&xwr->values, XATTR_VALUE_BUCKETS))
+ goto fail_values;
+
+ xwr->max_pairs = XATTR_INITIAL_PAIR_CAP;
+ xwr->kv_pairs = alloc_array(sizeof(xwr->kv_pairs[0]), xwr->max_pairs);
+
+ if (xwr->kv_pairs == NULL)
+ goto fail_pairs;
+
+ return xwr;
+fail_pairs:
+ str_table_cleanup(&xwr->values);
+fail_values:
+ str_table_cleanup(&xwr->keys);
+fail_keys:
+ free(xwr);
+ return NULL;
+}
+
+void sqfs_xattr_writer_destroy(sqfs_xattr_writer_t *xwr)
+{
+ kv_block_desc_t *blk;
+
+ while (xwr->kv_blocks != NULL) {
+ blk = xwr->kv_blocks;
+ xwr->kv_blocks = xwr->kv_blocks->next;
+ free(blk);
+ }
+
+ free(xwr->kv_pairs);
+ str_table_cleanup(&xwr->values);
+ str_table_cleanup(&xwr->keys);
+ free(xwr);
+}
+
+int sqfs_xattr_writer_begin(sqfs_xattr_writer_t *xwr)
+{
+ xwr->kv_start = xwr->num_pairs;
+ return 0;
+}
+
+int sqfs_xattr_writer_add(sqfs_xattr_writer_t *xwr, const char *key,
+ const void *value, size_t size)
+{
+ size_t i, key_index, old_value_index, value_index, new_count;
+ sqfs_u64 kv_pair, *new;
+ char *value_str;
+ int err;
+
+ if (!sqfs_has_xattr(key))
+ return SQFS_ERROR_UNSUPPORTED;
+
+ /* resolve key and value into unique, incremental IDs */
+ err = str_table_get_index(&xwr->keys, key, &key_index);
+ if (err)
+ return err;
+
+ value_str = to_base32(value, size);
+ if (value_str == NULL)
+ return SQFS_ERROR_ALLOC;
+
+ err = str_table_get_index(&xwr->values, value_str, &value_index);
+ free(value_str);
+ if (err)
+ return err;
+
+ str_table_add_ref(&xwr->values, value_index);
+
+ if (sizeof(size_t) > sizeof(sqfs_u32)) {
+ if (key_index > 0x0FFFFFFFFUL || value_index > 0x0FFFFFFFFUL)
+ return SQFS_ERROR_OVERFLOW;
+ }
+
+ /* bail if already have the pair, overwrite if we have the key */
+ kv_pair = MK_PAIR(key_index, value_index);
+
+ for (i = xwr->kv_start; i < xwr->num_pairs; ++i) {
+ if (xwr->kv_pairs[i] == kv_pair)
+ return 0;
+
+ if (GET_KEY(xwr->kv_pairs[i]) == key_index) {
+ old_value_index = GET_VALUE(xwr->kv_pairs[i]);
+
+ str_table_del_ref(&xwr->values, old_value_index);
+
+ xwr->kv_pairs[i] = kv_pair;
+ return 0;
+ }
+ }
+
+ /* append it to the list */
+ if (xwr->max_pairs == xwr->num_pairs) {
+ new_count = xwr->max_pairs * 2;
+ new = realloc(xwr->kv_pairs,
+ sizeof(xwr->kv_pairs[0]) * new_count);
+
+ if (new == NULL)
+ return SQFS_ERROR_ALLOC;
+
+ xwr->kv_pairs = new;
+ xwr->max_pairs = new_count;
+ }
+
+ xwr->kv_pairs[xwr->num_pairs++] = kv_pair;
+ return 0;
+}
+
+int sqfs_xattr_writer_end(sqfs_xattr_writer_t *xwr, sqfs_u32 *out)
+{
+ kv_block_desc_t *blk, *blk_prev;
+ size_t i, count, value_idx;
+ sqfs_u32 index;
+ int ret;
+
+ count = xwr->num_pairs - xwr->kv_start;
+
+ qsort(xwr->kv_pairs + xwr->kv_start, count,
+ sizeof(xwr->kv_pairs[0]), compare_u64);
+
+ blk_prev = NULL;
+ blk = xwr->kv_blocks;
+ index = 0;
+
+ while (blk != NULL) {
+ if (blk->count == count) {
+ ret = memcmp(xwr->kv_pairs + blk->start,
+ xwr->kv_pairs + xwr->kv_start,
+ sizeof(xwr->kv_pairs[0]) * count);
+
+ if (ret == 0)
+ break;
+ }
+
+ if (index == 0xFFFFFFFF)
+ return SQFS_ERROR_OVERFLOW;
+
+ ++index;
+ blk_prev = blk;
+ blk = blk->next;
+ }
+
+ if (blk != NULL) {
+ for (i = 0; i < count; ++i) {
+ value_idx = GET_VALUE(xwr->kv_pairs[xwr->kv_start + i]);
+ str_table_del_ref(&xwr->values, value_idx);
+
+ value_idx = GET_VALUE(xwr->kv_pairs[blk->start + i]);
+ str_table_add_ref(&xwr->values, value_idx);
+ }
+
+ xwr->num_pairs = xwr->kv_start;
+ } else {
+ blk = calloc(1, sizeof(*blk));
+ if (blk == NULL)
+ return SQFS_ERROR_ALLOC;
+
+ blk->start = xwr->kv_start;
+ blk->count = count;
+
+ if (blk_prev == NULL) {
+ xwr->kv_blocks = blk;
+ } else {
+ blk_prev->next = blk;
+ }
+
+ xwr->num_blocks += 1;
+ }
+
+ *out = index;
+ return 0;
+}
+
+/*****************************************************************************/
+
+int sqfs_xattr_writer_flush(sqfs_xattr_writer_t *xwr, sqfs_file_t *file,
+ sqfs_super_t *super, sqfs_compressor_t *cmp)
+{
+ (void)xwr;
+ (void)file;
+ (void)super;
+ (void)cmp;
+ return 0;
+}