diff options
| -rw-r--r-- | include/meta_writer.h | 12 | ||||
| -rw-r--r-- | lib/sqfs/meta_writer.c | 122 | ||||
| -rw-r--r-- | lib/sqfs/serialize_fstree.c | 4 | ||||
| -rw-r--r-- | lib/sqfs/table.c | 2 | ||||
| -rw-r--r-- | lib/sqfs/write_xattr.c | 2 |
5 files changed, 108 insertions, 34 deletions
diff --git a/include/meta_writer.h b/include/meta_writer.h index df0c70c..c10dd16 100644 --- a/include/meta_writer.h +++ b/include/meta_writer.h @@ -22,8 +22,11 @@ typedef struct { typedef struct meta_writer_t meta_writer_t; /* Create a meta data reader using a given compressor to compress data. - Internally prints error message to stderr on failure. */ -meta_writer_t *meta_writer_create(int fd, compressor_t *cmp); + Internally prints error message to stderr on failure. + If keep_in_mem is true, the blocks are collected in memory and must + be explicitly flushed to disk using meta_write_write_to_file. +*/ +meta_writer_t *meta_writer_create(int fd, compressor_t *cmp, bool keep_in_mem); void meta_writer_destroy(meta_writer_t *m); @@ -41,6 +44,11 @@ void meta_writer_get_position(const meta_writer_t *m, uint64_t *block_start, /* Reset all internal state, including the current block start position. */ void meta_writer_reset(meta_writer_t *m); +/* If created with keep_in_mem true, write the collected blocks to disk. + Does not flush the current block. Writes error messages to stderr and + returns non-zero on failure. */ +int meta_write_write_to_file(meta_writer_t *m); + /* High level helper function that writes squashfs directory entries to a meta data writer. diff --git a/lib/sqfs/meta_writer.c b/lib/sqfs/meta_writer.c index 2dacaa0..ef869e7 100644 --- a/lib/sqfs/meta_writer.c +++ b/lib/sqfs/meta_writer.c @@ -8,6 +8,13 @@ #include <unistd.h> #include <stdio.h> +typedef struct meta_block_t { + struct meta_block_t *next; + + /* possibly compressed data with 2 byte header */ + uint8_t data[SQFS_META_BLOCK_SIZE + 2]; +} meta_block_t; + struct meta_writer_t { /* A byte offset into the uncompressed data of the current block */ size_t offset; @@ -22,13 +29,36 @@ struct meta_writer_t { compressor_t *cmp; /* The raw data chunk that data is appended to */ - uint8_t data[SQFS_META_BLOCK_SIZE + 2]; + uint8_t data[SQFS_META_BLOCK_SIZE]; - /* Scratch buffer for compressing data */ - uint8_t scratch[SQFS_META_BLOCK_SIZE + 2]; + bool keep_in_mem; + meta_block_t *list; + meta_block_t *list_end; }; -meta_writer_t *meta_writer_create(int fd, compressor_t *cmp) +static int write_block(int fd, meta_block_t *outblk) +{ + size_t count; + ssize_t ret; + + count = le16toh(((uint16_t *)outblk->data)[0]) & 0x7FFF; + + ret = write_retry(fd, outblk->data, count + 2); + + if (ret < 0) { + perror("writing meta data block"); + return -1; + } + + if ((size_t)ret < count) { + fputs("meta data written to file was truncated\n", stderr); + return -1; + } + + return 0; +} + +meta_writer_t *meta_writer_create(int fd, compressor_t *cmp, bool keep_in_mem) { meta_writer_t *m = calloc(1, sizeof(*m)); @@ -39,53 +69,71 @@ meta_writer_t *meta_writer_create(int fd, compressor_t *cmp) m->cmp = cmp; m->outfd = fd; + m->keep_in_mem = keep_in_mem; return m; } void meta_writer_destroy(meta_writer_t *m) { + meta_block_t *blk; + + while (m->list != NULL) { + blk = m->list; + m->list = blk->next; + free(blk); + } + free(m); } int meta_writer_flush(meta_writer_t *m) { - ssize_t ret, count; - void *ptr; + meta_block_t *outblk; + size_t count; + ssize_t ret; if (m->offset == 0) return 0; - ret = m->cmp->do_block(m->cmp, m->data + 2, m->offset, - m->scratch + 2, sizeof(m->scratch) - 2); - if (ret < 0) + outblk = calloc(1, sizeof(*outblk)); + if (outblk == NULL) { + perror("generating meta data block"); + return -1; + } + + ret = m->cmp->do_block(m->cmp, m->data, m->offset, + outblk->data + 2, sizeof(outblk->data) - 2); + if (ret < 0) { + free(outblk); return -1; + } if (ret > 0) { - ((uint16_t *)m->scratch)[0] = htole16(ret); + ((uint16_t *)outblk->data)[0] = htole16(ret); count = ret + 2; - ptr = m->scratch; } else { - ((uint16_t *)m->data)[0] = htole16(m->offset | 0x8000); + ((uint16_t *)outblk->data)[0] = htole16(m->offset | 0x8000); + memcpy(outblk->data + 2, m->data, m->offset); count = m->offset + 2; - ptr = m->data; - } - - ret = write_retry(m->outfd, ptr, count); - - if (ret < 0) { - perror("writing meta data"); - return -1; } - if (ret < count) { - fputs("meta data written to file was truncated\n", stderr); - return -1; + if (m->keep_in_mem) { + if (m->list == NULL) { + m->list = outblk; + } else { + m->list_end->next = outblk; + } + m->list_end = outblk; + ret = 0; + } else { + ret = write_block(m->outfd, outblk); + free(outblk); } memset(m->data, 0, sizeof(m->data)); m->offset = 0; m->block_offset += count; - return 0; + return ret; } int meta_writer_append(meta_writer_t *m, const void *data, size_t size) @@ -93,24 +141,24 @@ int meta_writer_append(meta_writer_t *m, const void *data, size_t size) size_t diff; while (size != 0) { - diff = sizeof(m->data) - 2 - m->offset; + diff = sizeof(m->data) - m->offset; if (diff == 0) { if (meta_writer_flush(m)) return -1; - diff = sizeof(m->data) - 2; + diff = sizeof(m->data); } if (diff > size) diff = size; - memcpy(m->data + 2 + m->offset, data, diff); + memcpy(m->data + m->offset, data, diff); m->offset += diff; size -= diff; data = (const char *)data + diff; } - if (m->offset == (sizeof(m->data) - 2)) + if (m->offset == sizeof(m->data)) return meta_writer_flush(m); return 0; @@ -128,3 +176,21 @@ void meta_writer_reset(meta_writer_t *m) m->block_offset = 0; m->offset = 0; } + +int meta_write_write_to_file(meta_writer_t *m) +{ + meta_block_t *blk; + + while (m->list != NULL) { + blk = m->list; + + if (write_block(m->outfd, blk)) + return -1; + + m->list = blk->next; + free(blk); + } + + m->list_end = NULL; + return 0; +} diff --git a/lib/sqfs/serialize_fstree.c b/lib/sqfs/serialize_fstree.c index 44aeca4..f3e7bba 100644 --- a/lib/sqfs/serialize_fstree.c +++ b/lib/sqfs/serialize_fstree.c @@ -26,11 +26,11 @@ int sqfs_serialize_fstree(int outfd, sqfs_super_t *super, fstree_t *fs, tmpfd = fileno(tmp); - im = meta_writer_create(outfd, cmp); + im = meta_writer_create(outfd, cmp, false); if (im == NULL) goto fail_tmp; - dm = meta_writer_create(tmpfd, cmp); + dm = meta_writer_create(tmpfd, cmp, false); if (dm == NULL) goto fail_im; diff --git a/lib/sqfs/table.c b/lib/sqfs/table.c index abc95bd..fb6bddc 100644 --- a/lib/sqfs/table.c +++ b/lib/sqfs/table.c @@ -19,7 +19,7 @@ int sqfs_write_table(int outfd, sqfs_super_t *super, const void *data, /* Write actual data. Whenever we cross a block boundary, remember the block start offset */ - m = meta_writer_create(outfd, cmp); + m = meta_writer_create(outfd, cmp, false); if (m == NULL) return -1; diff --git a/lib/sqfs/write_xattr.c b/lib/sqfs/write_xattr.c index e81f677..0e11757 100644 --- a/lib/sqfs/write_xattr.c +++ b/lib/sqfs/write_xattr.c @@ -110,7 +110,7 @@ int write_xattr(int outfd, fstree_t *fs, sqfs_super_t *super, if (fs->xattr == NULL) return 0; - mw = meta_writer_create(outfd, cmp); + mw = meta_writer_create(outfd, cmp, false); if (mw == NULL) return -1; |