1 files changed, 200 insertions, 0 deletions
diff --git a/lib/sqfs/data_writer.c b/lib/sqfs/data_writer.c
new file mode 100644
index 0000000..a11e572
--- /dev/null
+++ b/lib/sqfs/data_writer.c
@@ -0,0 +1,200 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "data_writer.h"
+#include "highlevel.h"
+#include "util.h"
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <errno.h>
+
+struct data_writer_t {
+	void *block;
+	void *fragment;
+	void *scratch;
+
+	sqfs_fragment_t *fragments;
+	size_t num_fragments;
+	size_t max_fragments;
+	size_t frag_offset;
+
+	sqfs_super_t *super;
+	compressor_t *cmp;
+	int outfd;
+};
+
+static int write_compressed(data_writer_t *data, const void *in, size_t size,
+			    uint32_t *outsize)
+{
+	ssize_t ret;
+
+	ret = data->cmp->do_block(data->cmp, in, size, data->scratch,
+				  data->super->block_size);
+	if (ret < 0)
+		return -1;
+
+	if (ret > 0 && (size_t)ret < size) {
+		size = ret;
+		ret = write_retry(data->outfd, data->scratch, size);
+		*outsize = size;
+	} else {
+		ret = write_retry(data->outfd, in, size);
+		*outsize = size | (1 << 24);
+	}
+
+	if (ret < 0) {
+		perror("writing to output file");
+		return -1;
+	}
+
+	if ((size_t)ret < size) {
+		fputs("write to output file truncated\n", stderr);
+		return -1;
+	}
+
+	data->super->bytes_used += ret;
+	return 0;
+}
+
+static int grow_fragment_table(data_writer_t *data)
+{
+	size_t newsz;
+	void *new;
+
+	if (data->num_fragments == data->max_fragments) {
+		newsz = data->max_fragments ? data->max_fragments * 2 : 16;
+		new = realloc(data->fragments,
+			      sizeof(data->fragments[0]) * newsz);
+
+		if (new == NULL) {
+			perror("appending to fragment table");
+			return -1;
+		}
+
+		data->max_fragments = newsz;
+		data->fragments = new;
+	}
+
+	return 0;
+}
+
+int data_writer_flush_fragments(data_writer_t *data)
+{
+	uint64_t offset;
+	uint32_t out;
+
+	if (grow_fragment_table(data))
+		return -1;
+
+	offset = data->super->bytes_used;
+
+	if (write_compressed(data, data->fragment, data->frag_offset, &out))
+		return -1;
+
+	data->fragments[data->num_fragments].start_offset = htole64(offset);
+	data->fragments[data->num_fragments].pad0 = 0;
+	data->fragments[data->num_fragments].size = htole32(out);
+
+	data->num_fragments += 1;
+	data->frag_offset = 0;
+
+	data->super->flags &= ~SQFS_FLAG_NO_FRAGMENTS;
+	data->super->flags |= SQFS_FLAG_ALWAYS_FRAGMENTS;
+	return 0;
+}
+
+int write_data_from_fd(data_writer_t *data, file_info_t *fi, int infd)
+{
+	uint64_t count = fi->size;
+	int blk_idx = 0;
+	uint32_t out;
+	ssize_t ret;
+	size_t diff;
+
+	fi->startblock = data->super->bytes_used;
+
+	while (count != 0) {
+		diff = count > (uint64_t)data->super->block_size ?
+			data->super->block_size : count;
+
+		ret = read_retry(infd, data->block, diff);
+		if (ret < 0)
+			goto fail_read;
+		if ((size_t)ret < diff)
+			goto fail_trunc;
+
+		if (diff < data->super->block_size) {
+			if (data->frag_offset + diff > data->super->block_size) {
+				if (data_writer_flush_fragments(data))
+					return -1;
+			}
+
+			fi->fragment_offset = data->frag_offset;
+			fi->fragment = data->num_fragments;
+
+			memcpy((char *)data->fragment + data->frag_offset,
+			       data->block, diff);
+			data->frag_offset += diff;
+		} else {
+			if (write_compressed(data, data->block,
+					     data->super->block_size, &out)) {
+				return -1;
+			}
+
+			fi->blocksizes[blk_idx++] = out;
+		}
+
+		count -= diff;
+	}
+
+	return 0;
+fail_read:
+	fprintf(stderr, "read from %s: %s\n", fi->input_file, strerror(errno));
+	return -1;
+fail_trunc:
+	fprintf(stderr, "%s: truncated read\n", fi->input_file);
+	return -1;
+}
+
+data_writer_t *data_writer_create(sqfs_super_t *super, compressor_t *cmp,
+				  int outfd)
+{
+	data_writer_t *data;
+
+	data = calloc(1, sizeof(*data) + super->block_size * 3);
+	if (data == NULL) {
+		perror("creating data writer");
+		return NULL;
+	}
+
+	data->block = (char *)data + sizeof(*data);
+	data->fragment = (char *)data->block + super->block_size;
+	data->scratch = (char *)data->fragment + super->block_size;
+
+	data->super = super;
+	data->cmp = cmp;
+	data->outfd = outfd;
+	return data;
+}
+
+void data_writer_destroy(data_writer_t *data)
+{
+	free(data->fragments);
+	free(data);
+}
+
+int data_writer_write_fragment_table(data_writer_t *data)
+{
+	uint64_t start;
+
+	data->super->fragment_entry_count = data->num_fragments;
+
+	if (sqfs_write_table(data->outfd, data->super, data->fragments,
+			     sizeof(data->fragments[0]), data->num_fragments,
+			     &start, data->cmp)) {
+		return -1;
+	}
+
+	data->super->fragment_table_start = start;
+	return 0;
+}