Cleanup: split libsquashfs xattr writer code

This commit moves the libsquashfs xattr related code into a sub
directory and splits the xattr writer code up into several files.
No actual code is changed.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

7 files changed, 361 insertions, 335 deletions

diff --git a/lib/sqfs/Makemodule.am b/lib/sqfs/Makemodule.am
index 61c9b09..85f4aad 100644
--- a/lib/sqfs/Makemodule.am
+++ b/lib/sqfs/Makemodule.am
@@ -11,15 +11,18 @@ LIBSQFS_HEARDS = include/sqfs/meta_writer.h \
 		include/sqfs/frag_table.h include/sqfs/block_writer.h
 
 libsquashfs_la_SOURCES = $(LIBSQFS_HEARDS) lib/sqfs/id_table.c lib/sqfs/super.c
-libsquashfs_la_SOURCES += lib/sqfs/readdir.c lib/sqfs/xattr.c
+libsquashfs_la_SOURCES += lib/sqfs/readdir.c lib/sqfs/xattr/xattr.c
 libsquashfs_la_SOURCES += lib/sqfs/write_table.c lib/sqfs/meta_writer.c
 libsquashfs_la_SOURCES += lib/sqfs/read_super.c lib/sqfs/meta_reader.c
 libsquashfs_la_SOURCES += lib/sqfs/read_inode.c lib/sqfs/write_inode.c
-libsquashfs_la_SOURCES += lib/sqfs/dir_writer.c lib/sqfs/xattr_reader.c
+libsquashfs_la_SOURCES += lib/sqfs/dir_writer.c lib/sqfs/xattr/xattr_reader.c
 libsquashfs_la_SOURCES += lib/sqfs/read_table.c lib/sqfs/comp/compressor.c
-libsquashfs_la_SOURCES += lib/sqfs/comp/internal.h lib/sqfs/xattr_writer.c
+libsquashfs_la_SOURCES += lib/sqfs/comp/internal.h
 libsquashfs_la_SOURCES += lib/sqfs/dir_reader.c lib/sqfs/read_tree.c
-libsquashfs_la_SOURCES += lib/sqfs/inode.c
+libsquashfs_la_SOURCES += lib/sqfs/inode.c lib/sqfs/xattr/xattr_writer.c
+libsquashfs_la_SOURCES += lib/sqfs/xattr/xattr_writer_flush.c
+libsquashfs_la_SOURCES += lib/sqfs/xattr/xattr_writer_record.c
+libsquashfs_la_SOURCES += lib/sqfs/xattr/xattr_writer.h
 libsquashfs_la_SOURCES += lib/sqfs/write_super.c lib/sqfs/data_reader.c
 libsquashfs_la_SOURCES += lib/sqfs/block_processor/internal.h
 libsquashfs_la_SOURCES += lib/sqfs/block_processor/common.c
diff --git a/lib/sqfs/xattr.c b/lib/sqfs/xattr/xattr.c
index 29ecebf..29ecebf 100644
--- a/lib/sqfs/xattr.c
+++ b/lib/sqfs/xattr/xattr.c
diff --git a/lib/sqfs/xattr_reader.c b/lib/sqfs/xattr/xattr_reader.c
index 37f222a..37f222a 100644
--- a/lib/sqfs/xattr_reader.c
+++ b/lib/sqfs/xattr/xattr_reader.c
diff --git a/lib/sqfs/xattr/xattr_writer.c b/lib/sqfs/xattr/xattr_writer.c
new file mode 100644
index 0000000..9de3823
--- /dev/null
+++ b/lib/sqfs/xattr/xattr_writer.c
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * xattr_writer.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "xattr_writer.h"
+
+static sqfs_object_t *xattr_writer_copy(const sqfs_object_t *obj)
+{
+	const sqfs_xattr_writer_t *xwr = (const sqfs_xattr_writer_t *)obj;
+	kv_block_desc_t *blk, *it, **next;
+	sqfs_xattr_writer_t *copy;
+
+	copy = calloc(1, sizeof(*copy));
+	if (copy == NULL)
+		return NULL;
+
+	memcpy(copy, xwr, sizeof(*xwr));
+
+	if (str_table_copy(&copy->keys, &xwr->keys))
+		goto fail_keys;
+
+	if (str_table_copy(&copy->values, &xwr->values))
+		goto fail_values;
+
+	copy->max_pairs = xwr->num_pairs;
+	copy->num_pairs = xwr->num_pairs;
+
+	copy->kv_pairs = malloc(sizeof(copy->kv_pairs[0]) * xwr->num_pairs);
+	if (copy->kv_pairs == NULL)
+		goto fail_pairs;
+
+	memcpy(copy->kv_pairs, xwr->kv_pairs,
+	       sizeof(copy->kv_pairs[0]) * xwr->num_pairs);
+
+	next = &(copy->kv_blocks);
+
+	for (it = xwr->kv_blocks; it != NULL; it = it->next) {
+		blk = malloc(sizeof(*blk));
+		if (blk == NULL)
+			goto fail_blk;
+
+		memcpy(blk, it, sizeof(*it));
+		blk->next = NULL;
+
+		*next = blk;
+		next = &(blk->next);
+	}
+
+	return (sqfs_object_t *)copy;
+fail_blk:
+	while (copy->kv_blocks != NULL) {
+		blk = copy->kv_blocks;
+		copy->kv_blocks = copy->kv_blocks->next;
+		free(blk);
+	}
+fail_pairs:
+	str_table_cleanup(&copy->values);
+fail_values:
+	str_table_cleanup(&copy->keys);
+fail_keys:
+	free(copy);
+	return NULL;
+}
+
+static void xattr_writer_destroy(sqfs_object_t *obj)
+{
+	sqfs_xattr_writer_t *xwr = (sqfs_xattr_writer_t *)obj;
+	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);
+}
+
+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;
+
+	((sqfs_object_t *)xwr)->copy = xattr_writer_copy;
+	((sqfs_object_t *)xwr)->destroy = xattr_writer_destroy;
+	return xwr;
+fail_pairs:
+	str_table_cleanup(&xwr->values);
+fail_values:
+	str_table_cleanup(&xwr->keys);
+fail_keys:
+	free(xwr);
+	return NULL;
+}
diff --git a/lib/sqfs/xattr/xattr_writer.h b/lib/sqfs/xattr/xattr_writer.h
new file mode 100644
index 0000000..826b6f6
--- /dev/null
+++ b/lib/sqfs/xattr/xattr_writer.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * xattr_writer.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef XATTR_WRITER_H
+#define XATTR_WRITER_H
+
+#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>
+#include <assert.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)
+
+
+typedef struct kv_block_desc_t {
+	struct kv_block_desc_t *next;
+	size_t start;
+	size_t count;
+
+	sqfs_u64 start_ref;
+	size_t size_bytes;
+} kv_block_desc_t;
+
+struct sqfs_xattr_writer_t {
+	sqfs_object_t base;
+
+	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;
+};
+
+#endif /* XATTR_WRITER_H */
diff --git a/lib/sqfs/xattr_writer.c b/lib/sqfs/xattr/xattr_writer_flush.c
index 488fd43..9b3de30 100644
--- a/lib/sqfs/xattr_writer.c
+++ b/lib/sqfs/xattr/xattr_writer_flush.c
@@ -1,60 +1,13 @@
 /* SPDX-License-Identifier: LGPL-3.0-or-later */
 /*
- * xattr_writer.c
+ * xattr_writer_flush.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>
-#include <assert.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)
-
+#include "xattr_writer.h"
 
 static const char *hexmap = "0123456789ABCDEF";
 
-static char *to_base32(const void *input, size_t size)
-{
-	const sqfs_u8 *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)
 {
 	sqfs_u8 lo, hi, *out, *ptr;
@@ -79,288 +32,6 @@ static void *from_base32(const char *input, size_t *size_out)
 	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;
-
-	sqfs_u64 start_ref;
-	size_t size_bytes;
-} kv_block_desc_t;
-
-struct sqfs_xattr_writer_t {
-	sqfs_object_t base;
-
-	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;
-};
-
-
-static sqfs_object_t *xattr_writer_copy(const sqfs_object_t *obj)
-{
-	const sqfs_xattr_writer_t *xwr = (const sqfs_xattr_writer_t *)obj;
-	kv_block_desc_t *blk, *it, **next;
-	sqfs_xattr_writer_t *copy;
-
-	copy = calloc(1, sizeof(*copy));
-	if (copy == NULL)
-		return NULL;
-
-	memcpy(copy, xwr, sizeof(*xwr));
-
-	if (str_table_copy(&copy->keys, &xwr->keys))
-		goto fail_keys;
-
-	if (str_table_copy(&copy->values, &xwr->values))
-		goto fail_values;
-
-	copy->max_pairs = xwr->num_pairs;
-	copy->num_pairs = xwr->num_pairs;
-
-	copy->kv_pairs = malloc(sizeof(copy->kv_pairs[0]) * xwr->num_pairs);
-	if (copy->kv_pairs == NULL)
-		goto fail_pairs;
-
-	memcpy(copy->kv_pairs, xwr->kv_pairs,
-	       sizeof(copy->kv_pairs[0]) * xwr->num_pairs);
-
-	next = &(copy->kv_blocks);
-
-	for (it = xwr->kv_blocks; it != NULL; it = it->next) {
-		blk = malloc(sizeof(*blk));
-		if (blk == NULL)
-			goto fail_blk;
-
-		memcpy(blk, it, sizeof(*it));
-		blk->next = NULL;
-
-		*next = blk;
-		next = &(blk->next);
-	}
-
-	return (sqfs_object_t *)copy;
-fail_blk:
-	while (copy->kv_blocks != NULL) {
-		blk = copy->kv_blocks;
-		copy->kv_blocks = copy->kv_blocks->next;
-		free(blk);
-	}
-fail_pairs:
-	str_table_cleanup(&copy->values);
-fail_values:
-	str_table_cleanup(&copy->keys);
-fail_keys:
-	free(copy);
-	return NULL;
-}
-
-static void xattr_writer_destroy(sqfs_object_t *obj)
-{
-	sqfs_xattr_writer_t *xwr = (sqfs_xattr_writer_t *)obj;
-	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);
-}
-
-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;
-
-	((sqfs_object_t *)xwr)->copy = xattr_writer_copy;
-	((sqfs_object_t *)xwr)->destroy = xattr_writer_destroy;
-	return xwr;
-fail_pairs:
-	str_table_cleanup(&xwr->values);
-fail_values:
-	str_table_cleanup(&xwr->keys);
-fail_keys:
-	free(xwr);
-	return NULL;
-}
-
-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_get_xattr_prefix_id(key) < 0)
-		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;
-	if (count == 0) {
-		*out = 0xFFFFFFFF;
-		return 0;
-	}
-
-	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;
-}
-
-/*****************************************************************************/
-
 static sqfs_s32 write_key(sqfs_meta_writer_t *mw, const char *key,
 			  bool value_is_ool)
 {
diff --git a/lib/sqfs/xattr/xattr_writer_record.c b/lib/sqfs/xattr/xattr_writer_record.c
new file mode 100644
index 0000000..5e97868
--- /dev/null
+++ b/lib/sqfs/xattr/xattr_writer_record.c
@@ -0,0 +1,179 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * xattr_writer_record.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "xattr_writer.h"
+
+static const char *hexmap = "0123456789ABCDEF";
+
+static char *to_base32(const void *input, size_t size)
+{
+	const sqfs_u8 *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 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));
+}
+
+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_get_xattr_prefix_id(key) < 0)
+		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;
+	if (count == 0) {
+		*out = 0xFFFFFFFF;
+		return 0;
+	}
+
+	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;
+}