From 77b2c74599190197074c82937787f24f83ece0af Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 17 May 2013 15:28:49 -0500 Subject: [PATCH 1/1] write.c: Build up chunk offsets array in little-endian format --- include/wimlib/endianness.h | 28 ---------------- src/write.c | 64 +++++++++++++++++++++++-------------- 2 files changed, 40 insertions(+), 52 deletions(-) diff --git a/include/wimlib/endianness.h b/include/wimlib/endianness.h index 2d1e9a67..3cefe68e 100644 --- a/include/wimlib/endianness.h +++ b/include/wimlib/endianness.h @@ -54,32 +54,4 @@ bswap64(u64 n) # endif #endif /* _NTFS_ENDIANS_H */ -static inline void -array_cpu_to_le32(u32 *p, size_t n) -{ - for (size_t i = 0; i < n; i++) - p[i] = cpu_to_le32(p[i]); -} - -static inline void -array_le32_to_cpu(u32 *p, size_t n) -{ - for (size_t i = 0; i < n; i++) - p[i] = le32_to_cpu(p[i]); -} - -static inline void -array_cpu_to_le64(u64 *p, size_t n) -{ - for (size_t i = 0; i < n; i++) - p[i] = cpu_to_le64(p[i]); -} - -static inline void -array_le64_to_cpu(u64 *p, size_t n) -{ - for (size_t i = 0; i < n; i++) - p[i] = le64_to_cpu(p[i]); -} - #endif /* _WIMLIB_ENDIANNESS_H */ diff --git a/src/write.c b/src/write.c index fde7e939..90dcaed4 100644 --- a/src/write.c +++ b/src/write.c @@ -81,16 +81,19 @@ * array of offsets.) */ struct chunk_table { off_t file_offset; - u64 num_chunks; u64 original_resource_size; - u64 bytes_per_chunk_entry; + u64 num_chunks; u64 table_disk_size; - u64 cur_offset; - u64 *cur_offset_p; + unsigned bytes_per_chunk_entry; + void *cur_offset_p; union { - u64 offsets[0]; - u32 u32_offsets[0]; + u32 cur_offset_u32; + u64 cur_offset_u64; }; + /* Beginning of chunk offsets, in either 32-bit or 64-bit little endian + * integers, including the first offset of 0, which will not be written. + * */ + u8 offsets[] _aligned_attribute(8); }; /* @@ -105,10 +108,11 @@ begin_wim_resource_chunk_tab(const struct wim_lookup_table_entry *lte, { u64 size = wim_resource_size(lte); u64 num_chunks = wim_resource_chunks(lte); + unsigned bytes_per_chunk_entry = (size > (1ULL << 32)) ? 8 : 4; size_t alloc_size = sizeof(struct chunk_table) + num_chunks * sizeof(u64); struct chunk_table *chunk_tab = CALLOC(1, alloc_size); - DEBUG("Begin chunk table for stream with size %"PRIu64, size); + DEBUG("Beginning chunk table for stream with size %"PRIu64, size); if (!chunk_tab) { ERROR("Failed to allocate chunk table for %"PRIu64" byte " @@ -118,13 +122,15 @@ begin_wim_resource_chunk_tab(const struct wim_lookup_table_entry *lte, chunk_tab->file_offset = file_offset; chunk_tab->num_chunks = num_chunks; chunk_tab->original_resource_size = size; - chunk_tab->bytes_per_chunk_entry = (size > (1ULL << 32)) ? 8 : 4; + chunk_tab->bytes_per_chunk_entry = bytes_per_chunk_entry; chunk_tab->table_disk_size = chunk_tab->bytes_per_chunk_entry * (num_chunks - 1); - chunk_tab->cur_offset = 0; chunk_tab->cur_offset_p = chunk_tab->offsets; - if (full_write(out_fd, chunk_tab, + /* We don't know the correct offsets yet; this just writes zeroes to + * reserve space for the table, so we can go back to it later after + * we've written the compressed chunks following it. */ + if (full_write(out_fd, chunk_tab->offsets, chunk_tab->table_disk_size) != chunk_tab->table_disk_size) { ERROR_WITH_ERRNO("Failed to write chunk table in compressed " @@ -136,6 +142,22 @@ begin_wim_resource_chunk_tab(const struct wim_lookup_table_entry *lte, return 0; } +/* Add the offset for the next chunk to the chunk table being constructed for a + * compressed stream. */ +static void +chunk_tab_record_chunk(struct chunk_table *chunk_tab, unsigned out_chunk_size) +{ + if (chunk_tab->bytes_per_chunk_entry == 4) { + *(le32*)chunk_tab->cur_offset_p = cpu_to_le32(chunk_tab->cur_offset_u32); + chunk_tab->cur_offset_p = (le32*)chunk_tab->cur_offset_p + 1; + chunk_tab->cur_offset_u32 += out_chunk_size; + } else { + *(le64*)chunk_tab->cur_offset_p = cpu_to_le64(chunk_tab->cur_offset_u64); + chunk_tab->cur_offset_p = (le64*)chunk_tab->cur_offset_p + 1; + chunk_tab->cur_offset_u64 += out_chunk_size; + } +} + /* * compress_func_t- Pointer to a function to compresses a chunk * of a WIM resource. This may be either @@ -205,8 +227,7 @@ write_wim_resource_chunk(const void * restrict chunk, out_chunk = chunk; out_chunk_size = chunk_size; } - *chunk_tab->cur_offset_p++ = chunk_tab->cur_offset; - chunk_tab->cur_offset += out_chunk_size; + chunk_tab_record_chunk(chunk_tab, out_chunk_size); } else { /* Write uncompressed */ out_chunk = chunk; @@ -232,14 +253,8 @@ finish_wim_resource_chunk_tab(struct chunk_table *chunk_tab, { size_t bytes_written; - if (chunk_tab->bytes_per_chunk_entry == 8) { - array_cpu_to_le64(chunk_tab->offsets, chunk_tab->num_chunks); - } else { - for (u64 i = 0; i < chunk_tab->num_chunks; i++) - chunk_tab->u32_offsets[i] = cpu_to_le32(chunk_tab->offsets[i]); - } bytes_written = full_pwrite(out_fd, - (u8*)chunk_tab->offsets + chunk_tab->bytes_per_chunk_entry, + chunk_tab->offsets + chunk_tab->bytes_per_chunk_entry, chunk_tab->table_disk_size, chunk_tab->file_offset); if (bytes_written != chunk_tab->table_disk_size) { @@ -247,7 +262,10 @@ finish_wim_resource_chunk_tab(struct chunk_table *chunk_tab, "file resource"); return WIMLIB_ERR_WRITE; } - *compressed_size_p = chunk_tab->cur_offset + chunk_tab->table_disk_size; + if (chunk_tab->bytes_per_chunk_entry == 4) + *compressed_size_p = chunk_tab->cur_offset_u32 + chunk_tab->table_disk_size; + else + *compressed_size_p = chunk_tab->cur_offset_u64 + chunk_tab->table_disk_size; return 0; } @@ -793,10 +811,8 @@ static int write_wim_chunks(struct message *msg, int out_fd, struct chunk_table *chunk_tab) { - for (unsigned i = 0; i < msg->num_chunks; i++) { - *chunk_tab->cur_offset_p++ = chunk_tab->cur_offset; - chunk_tab->cur_offset += msg->out_chunks[i].iov_len; - } + for (unsigned i = 0; i < msg->num_chunks; i++) + chunk_tab_record_chunk(chunk_tab, msg->out_chunks[i].iov_len); if (full_writev(out_fd, msg->out_chunks, msg->num_chunks) != msg->total_out_bytes) { -- 2.43.0