75 lines
1.2 KiB
C
75 lines
1.2 KiB
C
#include "config.h"
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#include <bitcoin/varint.h>
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size_t varint_size(varint_t v)
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{
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if (v < 0xfd)
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return 1;
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if (v <= 0xffff)
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return 3;
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if (v <= 0xffffffff)
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return 5;
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return 9;
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}
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size_t varint_put(u8 buf[VARINT_MAX_LEN], varint_t v)
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{
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u8 *p = buf;
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if (v < 0xfd) {
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*(p++) = v;
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} else if (v <= 0xffff) {
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(*p++) = 0xfd;
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(*p++) = v;
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(*p++) = v >> 8;
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} else if (v <= 0xffffffff) {
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(*p++) = 0xfe;
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(*p++) = v;
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(*p++) = v >> 8;
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(*p++) = v >> 16;
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(*p++) = v >> 24;
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} else {
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(*p++) = 0xff;
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(*p++) = v;
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(*p++) = v >> 8;
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(*p++) = v >> 16;
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(*p++) = v >> 24;
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(*p++) = v >> 32;
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(*p++) = v >> 40;
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(*p++) = v >> 48;
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(*p++) = v >> 56;
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}
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return p - buf;
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}
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size_t varint_get(const u8 *p, size_t max, varint_t *val)
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{
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if (max < 1)
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return 0;
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switch (*p) {
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case 0xfd:
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if (max < 3)
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return 0;
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*val = ((u64)p[2] << 8) + p[1];
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return 3;
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case 0xfe:
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if (max < 5)
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return 0;
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*val = ((u64)p[4] << 24) + ((u64)p[3] << 16)
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+ ((u64)p[2] << 8) + p[1];
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return 5;
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case 0xff:
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if (max < 9)
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return 0;
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*val = ((u64)p[8] << 56) + ((u64)p[7] << 48)
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+ ((u64)p[6] << 40) + ((u64)p[5] << 32)
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+ ((u64)p[4] << 24) + ((u64)p[3] << 16)
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+ ((u64)p[2] << 8) + p[1];
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return 9;
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default:
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*val = *p;
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return 1;
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}
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}
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