35 lines
919 B
C
35 lines
919 B
C
#ifndef DELTA_H
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#define DELTA_H
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/* handling of delta buffers */
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extern void *diff_delta(void *from_buf, unsigned long from_size,
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void *to_buf, unsigned long to_size,
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unsigned long *delta_size, unsigned long max_size);
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extern void *patch_delta(void *src_buf, unsigned long src_size,
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void *delta_buf, unsigned long delta_size,
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unsigned long *dst_size);
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/* the smallest possible delta size is 4 bytes */
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#define DELTA_SIZE_MIN 4
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/*
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* This must be called twice on the delta data buffer, first to get the
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* expected reference buffer size, and again to get the result buffer size.
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*/
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static inline unsigned long get_delta_hdr_size(const unsigned char **datap)
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{
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const unsigned char *data = *datap;
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unsigned char cmd = *data++;
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unsigned long size = cmd & ~0x80;
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int i = 7;
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while (cmd & 0x80) {
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cmd = *data++;
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size |= (cmd & ~0x80) << i;
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i += 7;
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}
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*datap = data;
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return size;
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}
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#endif
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