116 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
			
		
		
	
	
			116 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
/*
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 * csum-file.c
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 *
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 * Copyright (C) 2005 Linus Torvalds
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 *
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 * Simple file write infrastructure for writing SHA1-summed
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 * files. Useful when you write a file that you want to be
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 * able to verify hasn't been messed with afterwards.
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 */
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#include "cache.h"
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#include "progress.h"
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#include "csum-file.h"
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static void sha1flush(struct sha1file *f, unsigned int count)
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{
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	void *buf = f->buffer;
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	for (;;) {
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		int ret = xwrite(f->fd, buf, count);
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		if (ret > 0) {
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			f->total += ret;
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			display_throughput(f->tp, f->total);
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			buf = (char *) buf + ret;
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			count -= ret;
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			if (count)
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				continue;
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			return;
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		}
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		if (!ret)
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			die("sha1 file '%s' write error. Out of diskspace", f->name);
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		die("sha1 file '%s' write error (%s)", f->name, strerror(errno));
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	}
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}
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int sha1close(struct sha1file *f, unsigned char *result, unsigned int flags)
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{
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	int fd;
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	unsigned offset = f->offset;
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	if (offset) {
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		SHA1_Update(&f->ctx, f->buffer, offset);
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		sha1flush(f, offset);
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		f->offset = 0;
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	}
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	if (flags & (CSUM_CLOSE | CSUM_FSYNC)) {
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		/* write checksum and close fd */
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		SHA1_Final(f->buffer, &f->ctx);
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		if (result)
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			hashcpy(result, f->buffer);
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		sha1flush(f, 20);
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		if (flags & CSUM_FSYNC)
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			fsync_or_die(f->fd, f->name);
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		if (close(f->fd))
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			die("%s: sha1 file error on close (%s)",
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			    f->name, strerror(errno));
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		fd = 0;
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	} else
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		fd = f->fd;
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	free(f);
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	return fd;
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}
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int sha1write(struct sha1file *f, void *buf, unsigned int count)
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{
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	if (f->do_crc)
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		f->crc32 = crc32(f->crc32, buf, count);
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	while (count) {
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		unsigned offset = f->offset;
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		unsigned left = sizeof(f->buffer) - offset;
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		unsigned nr = count > left ? left : count;
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		memcpy(f->buffer + offset, buf, nr);
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		count -= nr;
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		offset += nr;
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		buf = (char *) buf + nr;
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		left -= nr;
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		if (!left) {
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			SHA1_Update(&f->ctx, f->buffer, offset);
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			sha1flush(f, offset);
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			offset = 0;
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		}
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		f->offset = offset;
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	}
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	return 0;
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}
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struct sha1file *sha1fd(int fd, const char *name)
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{
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	return sha1fd_throughput(fd, name, NULL);
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}
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struct sha1file *sha1fd_throughput(int fd, const char *name, struct progress *tp)
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{
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	struct sha1file *f = xmalloc(sizeof(*f));
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	f->fd = fd;
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	f->offset = 0;
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	f->total = 0;
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	f->tp = tp;
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	f->name = name;
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	f->do_crc = 0;
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	SHA1_Init(&f->ctx);
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	return f;
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}
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void crc32_begin(struct sha1file *f)
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{
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	f->crc32 = crc32(0, Z_NULL, 0);
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	f->do_crc = 1;
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}
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uint32_t crc32_end(struct sha1file *f)
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{
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	f->do_crc = 0;
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	return f->crc32;
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}
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