Write out the missing tables

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

2 files changed, 95 insertions, 0 deletions

diff --git a/lib/Makemodule.am b/lib/Makemodule.am
index b12367d..7de4c83 100644
--- a/lib/Makemodule.am
+++ b/lib/Makemodule.am
@@ -9,6 +9,7 @@ libcompress_a_CPPFLAGS = $(AM_CPPFLAGS)
 libsquashfs_a_SOURCES = include/meta_writer.h include/squashfs.h
 libsquashfs_a_SOURCES += lib/sqfs/meta_writer.c lib/sqfs/super.c
 libsquashfs_a_SOURCES += lib/sqfs/id_table.c include/id_table.h
+libsquashfs_a_SOURCES += lib/sqfs/table.c include/table.h
 
 libutil_a_SOURCES = lib/util/canonicalize_name.c lib/util/write_retry.c
 libutil_a_SOURCES += lib/util/read_retry.c include/util.h
diff --git a/lib/sqfs/table.c b/lib/sqfs/table.c
new file mode 100644
index 0000000..2fab3cc
--- /dev/null
+++ b/lib/sqfs/table.c
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include "meta_writer.h"
+#include "table.h"
+#include "util.h"
+
+#include <endian.h>
+#include <stdio.h>
+
+static int sqfs_write_table(int outfd, sqfs_super_t *super, const void *data,
+			    size_t entsize, size_t count, uint64_t *startblock,
+			    compressor_t *cmp)
+{
+	size_t ent_per_blocks = SQFS_META_BLOCK_SIZE / entsize;
+	uint64_t blocks[count / ent_per_blocks + 1];
+	size_t i, blkidx = 0, tblsize;
+	meta_writer_t *m;
+	ssize_t ret;
+
+	/* Write actual data. Whenever we cross a block boundary, remember
+	   the block start offset */
+	m = meta_writer_create(outfd, cmp);
+	if (m == NULL)
+		return -1;
+
+	for (i = 0; i < count; ++i) {
+		if (blkidx == 0 || m->block_offset > blocks[blkidx - 1])
+			blocks[blkidx++] = m->block_offset;
+
+		if (meta_writer_append(m, data, entsize))
+			goto fail;
+
+		data = (const char *)data + entsize;
+	}
+
+	if (meta_writer_flush(m))
+		goto fail;
+
+	for (i = 0; i < blkidx; ++i)
+		blocks[i] = htole64(blocks[i] + super->bytes_used);
+
+	super->bytes_used += m->block_offset;
+	meta_writer_destroy(m);
+
+	/* write new index table */
+	*startblock = super->bytes_used;
+	tblsize = sizeof(blocks[0]) * blkidx;
+
+	ret = write_retry(outfd, blocks, tblsize);
+	if (ret < 0) {
+		perror("writing index table");
+		return -1;
+	}
+
+	if ((size_t)ret < tblsize) {
+		fputs("index table truncated\n", stderr);
+		return -1;
+	}
+
+	super->bytes_used += tblsize;
+	return 0;
+fail:
+	meta_writer_destroy(m);
+	return -1;
+}
+
+int sqfs_write_fragment_table(int outfd, sqfs_super_t *super,
+			      sqfs_fragment_t *fragments, size_t count,
+			      compressor_t *cmp)
+{
+	super->fragment_entry_count = count;
+
+	return sqfs_write_table(outfd, super, fragments, sizeof(fragments[0]),
+				count, &super->fragment_table_start, cmp);
+}
+
+int sqfs_write_ids(int outfd, sqfs_super_t *super, uint32_t *id_tbl,
+		   size_t count, compressor_t *cmp)
+{
+	size_t i;
+	int ret;
+
+	for (i = 0; i < count; ++i)
+		id_tbl[i] = htole32(id_tbl[i]);
+
+	super->id_count = count;
+
+	ret = sqfs_write_table(outfd, super, id_tbl, sizeof(id_tbl[0]),
+			       count, &super->id_table_start, cmp);
+
+	for (i = 0; i < count; ++i)
+		id_tbl[i] = htole32(id_tbl[i]);
+
+	return ret;
+}