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-rw-r--r--lib/sqfs/data_writer.c200
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;
+}