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