Import libsparse sources

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

libsparse/sparse.c

@@ -0,0 +1,332 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+
+#include <sparse/sparse.h>
+
+#include "defs.h"
+#include "sparse_file.h"
+
+#include "output_file.h"
+#include "backed_block.h"
+#include "sparse_defs.h"
+#include "sparse_format.h"
+
+struct sparse_file *sparse_file_new(unsigned int block_size, int64_t len)
+{
+	struct sparse_file *s = calloc(sizeof(struct sparse_file), 1);
+	if (!s) {
+		return NULL;
+	}
+
+	s->backed_block_list = backed_block_list_new(block_size);
+	if (!s->backed_block_list) {
+		free(s);
+		return NULL;
+	}
+
+	s->block_size = block_size;
+	s->len = len;
+
+	return s;
+}
+
+void sparse_file_destroy(struct sparse_file *s)
+{
+	backed_block_list_destroy(s->backed_block_list);
+	free(s);
+}
+
+int sparse_file_add_data(struct sparse_file *s,
+		void *data, unsigned int len, unsigned int block)
+{
+	return backed_block_add_data(s->backed_block_list, data, len, block);
+}
+
+int sparse_file_add_fill(struct sparse_file *s,
+		uint32_t fill_val, unsigned int len, unsigned int block)
+{
+	return backed_block_add_fill(s->backed_block_list, fill_val, len, block);
+}
+
+int sparse_file_add_file(struct sparse_file *s,
+		const char *filename, int64_t file_offset, unsigned int len,
+		unsigned int block)
+{
+	return backed_block_add_file(s->backed_block_list, filename, file_offset,
+			len, block);
+}
+
+int sparse_file_add_fd(struct sparse_file *s,
+		int fd, int64_t file_offset, unsigned int len, unsigned int block)
+{
+	return backed_block_add_fd(s->backed_block_list, fd, file_offset,
+			len, block);
+}
+unsigned int sparse_count_chunks(struct sparse_file *s)
+{
+	struct backed_block *bb;
+	unsigned int last_block = 0;
+	unsigned int chunks = 0;
+
+	for (bb = backed_block_iter_new(s->backed_block_list); bb;
+			bb = backed_block_iter_next(bb)) {
+		if (backed_block_block(bb) > last_block) {
+			/* If there is a gap between chunks, add a skip chunk */
+			chunks++;
+		}
+		chunks++;
+		last_block = backed_block_block(bb) +
+				DIV_ROUND_UP(backed_block_len(bb), s->block_size);
+	}
+	if (last_block < DIV_ROUND_UP(s->len, s->block_size)) {
+		chunks++;
+	}
+
+	return chunks;
+}
+
+static int sparse_file_write_block(struct output_file *out,
+		struct backed_block *bb)
+{
+	int ret = -EINVAL;
+
+	switch (backed_block_type(bb)) {
+	case BACKED_BLOCK_DATA:
+		ret = write_data_chunk(out, backed_block_len(bb), backed_block_data(bb));
+		break;
+	case BACKED_BLOCK_FILE:
+		ret = write_file_chunk(out, backed_block_len(bb),
+				       backed_block_filename(bb),
+				       backed_block_file_offset(bb));
+		break;
+	case BACKED_BLOCK_FD:
+		ret = write_fd_chunk(out, backed_block_len(bb),
+				     backed_block_fd(bb),
+				     backed_block_file_offset(bb));
+		break;
+	case BACKED_BLOCK_FILL:
+		ret = write_fill_chunk(out, backed_block_len(bb),
+				       backed_block_fill_val(bb));
+		break;
+	}
+
+	return ret;
+}
+
+static int write_all_blocks(struct sparse_file *s, struct output_file *out)
+{
+	struct backed_block *bb;
+	unsigned int last_block = 0;
+	int64_t pad;
+	int ret = 0;
+
+	for (bb = backed_block_iter_new(s->backed_block_list); bb;
+			bb = backed_block_iter_next(bb)) {
+		if (backed_block_block(bb) > last_block) {
+			unsigned int blocks = backed_block_block(bb) - last_block;
+			write_skip_chunk(out, (int64_t)blocks * s->block_size);
+		}
+		ret = sparse_file_write_block(out, bb);
+		if (ret)
+			return ret;
+		last_block = backed_block_block(bb) +
+				DIV_ROUND_UP(backed_block_len(bb), s->block_size);
+	}
+
+	pad = s->len - (int64_t)last_block * s->block_size;
+	assert(pad >= 0);
+	if (pad > 0) {
+		write_skip_chunk(out, pad);
+	}
+
+	return 0;
+}
+
+int sparse_file_write(struct sparse_file *s, int fd, bool gz, bool sparse,
+		bool crc)
+{
+	int ret;
+	int chunks;
+	struct output_file *out;
+
+	chunks = sparse_count_chunks(s);
+	out = output_file_open_fd(fd, s->block_size, s->len, gz, sparse, chunks, crc);
+
+	if (!out)
+		return -ENOMEM;
+
+	ret = write_all_blocks(s, out);
+
+	output_file_close(out);
+
+	return ret;
+}
+
+int sparse_file_callback(struct sparse_file *s, bool sparse, bool crc,
+		int (*write)(void *priv, const void *data, int len), void *priv)
+{
+	int ret;
+	int chunks;
+	struct output_file *out;
+
+	chunks = sparse_count_chunks(s);
+	out = output_file_open_callback(write, priv, s->block_size, s->len, false,
+			sparse, chunks, crc);
+
+	if (!out)
+		return -ENOMEM;
+
+	ret = write_all_blocks(s, out);
+
+	output_file_close(out);
+
+	return ret;
+}
+
+static int out_counter_write(void *priv, const void *data __unused, int len)
+{
+	int64_t *count = priv;
+	*count += len;
+	return 0;
+}
+
+int64_t sparse_file_len(struct sparse_file *s, bool sparse, bool crc)
+{
+	int ret;
+	int chunks = sparse_count_chunks(s);
+	int64_t count = 0;
+	struct output_file *out;
+
+	out = output_file_open_callback(out_counter_write, &count,
+			s->block_size, s->len, false, sparse, chunks, crc);
+	if (!out) {
+		return -1;
+	}
+
+	ret = write_all_blocks(s, out);
+
+	output_file_close(out);
+
+	if (ret < 0) {
+		return -1;
+	}
+
+	return count;
+}
+
+static struct backed_block *move_chunks_up_to_len(struct sparse_file *from,
+		struct sparse_file *to, unsigned int len)
+{
+	int64_t count = 0;
+	struct output_file *out_counter;
+	struct backed_block *last_bb = NULL;
+	struct backed_block *bb;
+	struct backed_block *start;
+	int64_t file_len = 0;
+	int ret;
+
+	/*
+	 * overhead is sparse file header, initial skip chunk, split chunk, end
+	 * skip chunk, and crc chunk.
+	 */
+	int overhead = sizeof(sparse_header_t) + 4 * sizeof(chunk_header_t) +
+			sizeof(uint32_t);
+	len -= overhead;
+
+	start = backed_block_iter_new(from->backed_block_list);
+	out_counter = output_file_open_callback(out_counter_write, &count,
+			to->block_size, to->len, false, true, 0, false);
+	if (!out_counter) {
+		return NULL;
+	}
+
+	for (bb = start; bb; bb = backed_block_iter_next(bb)) {
+		count = 0;
+		/* will call out_counter_write to update count */
+		ret = sparse_file_write_block(out_counter, bb);
+		if (ret) {
+			bb = NULL;
+			goto out;
+		}
+		if (file_len + count > len) {
+			/*
+			 * If the remaining available size is more than 1/8th of the
+			 * requested size, split the chunk.  Results in sparse files that
+			 * are at least 7/8ths of the requested size
+			 */
+			if (!last_bb || (len - file_len > (len / 8))) {
+				backed_block_split(from->backed_block_list, bb, len - file_len);
+				last_bb = bb;
+			}
+			goto move;
+		}
+		file_len += count;
+		last_bb = bb;
+	}
+
+move:
+	backed_block_list_move(from->backed_block_list,
+		to->backed_block_list, start, last_bb);
+
+out:
+	output_file_close(out_counter);
+
+	return bb;
+}
+
+int sparse_file_resparse(struct sparse_file *in_s, unsigned int max_len,
+		struct sparse_file **out_s, int out_s_count)
+{
+	struct backed_block *bb;
+	struct sparse_file *s;
+	struct sparse_file *tmp;
+	int c = 0;
+
+	tmp = sparse_file_new(in_s->block_size, in_s->len);
+	if (!tmp) {
+		return -ENOMEM;
+	}
+
+	do {
+		s = sparse_file_new(in_s->block_size, in_s->len);
+
+		bb = move_chunks_up_to_len(in_s, s, max_len);
+
+		if (c < out_s_count) {
+			out_s[c] = s;
+		} else {
+			backed_block_list_move(s->backed_block_list, tmp->backed_block_list,
+					NULL, NULL);
+			sparse_file_destroy(s);
+		}
+		c++;
+	} while (bb);
+
+	backed_block_list_move(tmp->backed_block_list, in_s->backed_block_list,
+			NULL, NULL);
+
+	sparse_file_destroy(tmp);
+
+	return c;
+}
+
+void sparse_file_verbose(struct sparse_file *s)
+{
+	s->verbose = true;
+}