| /* |
| Copyright 2020 Google LLC |
| |
| Use of this source code is governed by a BSD-style |
| license that can be found in the LICENSE file or at |
| https://developers.google.com/open-source/licenses/bsd |
| */ |
| |
| #include "system.h" |
| |
| #include "basics.h" |
| #include "blocksource.h" |
| #include "reftable-blocksource.h" |
| #include "reftable-error.h" |
| |
| static void strbuf_return_block(void *b, struct reftable_block *dest) |
| { |
| if (dest->len) |
| memset(dest->data, 0xff, dest->len); |
| reftable_free(dest->data); |
| } |
| |
| static void strbuf_close(void *b) |
| { |
| } |
| |
| static int strbuf_read_block(void *v, struct reftable_block *dest, uint64_t off, |
| uint32_t size) |
| { |
| struct strbuf *b = v; |
| assert(off + size <= b->len); |
| REFTABLE_CALLOC_ARRAY(dest->data, size); |
| memcpy(dest->data, b->buf + off, size); |
| dest->len = size; |
| return size; |
| } |
| |
| static uint64_t strbuf_size(void *b) |
| { |
| return ((struct strbuf *)b)->len; |
| } |
| |
| static struct reftable_block_source_vtable strbuf_vtable = { |
| .size = &strbuf_size, |
| .read_block = &strbuf_read_block, |
| .return_block = &strbuf_return_block, |
| .close = &strbuf_close, |
| }; |
| |
| void block_source_from_strbuf(struct reftable_block_source *bs, |
| struct strbuf *buf) |
| { |
| assert(!bs->ops); |
| bs->ops = &strbuf_vtable; |
| bs->arg = buf; |
| } |
| |
| static void malloc_return_block(void *b, struct reftable_block *dest) |
| { |
| if (dest->len) |
| memset(dest->data, 0xff, dest->len); |
| reftable_free(dest->data); |
| } |
| |
| static struct reftable_block_source_vtable malloc_vtable = { |
| .return_block = &malloc_return_block, |
| }; |
| |
| static struct reftable_block_source malloc_block_source_instance = { |
| .ops = &malloc_vtable, |
| }; |
| |
| struct reftable_block_source malloc_block_source(void) |
| { |
| return malloc_block_source_instance; |
| } |
| |
| struct file_block_source { |
| uint64_t size; |
| unsigned char *data; |
| }; |
| |
| static uint64_t file_size(void *b) |
| { |
| return ((struct file_block_source *)b)->size; |
| } |
| |
| static void file_return_block(void *b, struct reftable_block *dest) |
| { |
| } |
| |
| static void file_close(void *v) |
| { |
| struct file_block_source *b = v; |
| munmap(b->data, b->size); |
| reftable_free(b); |
| } |
| |
| static int file_read_block(void *v, struct reftable_block *dest, uint64_t off, |
| uint32_t size) |
| { |
| struct file_block_source *b = v; |
| assert(off + size <= b->size); |
| dest->data = b->data + off; |
| dest->len = size; |
| return size; |
| } |
| |
| static struct reftable_block_source_vtable file_vtable = { |
| .size = &file_size, |
| .read_block = &file_read_block, |
| .return_block = &file_return_block, |
| .close = &file_close, |
| }; |
| |
| int reftable_block_source_from_file(struct reftable_block_source *bs, |
| const char *name) |
| { |
| struct file_block_source *p; |
| struct stat st; |
| int fd; |
| |
| fd = open(name, O_RDONLY); |
| if (fd < 0) { |
| if (errno == ENOENT) |
| return REFTABLE_NOT_EXIST_ERROR; |
| return -1; |
| } |
| |
| if (fstat(fd, &st) < 0) { |
| close(fd); |
| return REFTABLE_IO_ERROR; |
| } |
| |
| REFTABLE_CALLOC_ARRAY(p, 1); |
| p->size = st.st_size; |
| p->data = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); |
| close(fd); |
| |
| assert(!bs->ops); |
| bs->ops = &file_vtable; |
| bs->arg = p; |
| return 0; |
| } |