git ssb

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#include <malloc.h>
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#include <string.h>
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#include <stdio.h>
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#include "foobuf.h"
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int foobuf_init(struct foobuf **bufp, size_t len)
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{
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	struct foobuf *buf = *bufp;
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	if (!buf) buf = calloc(sizeof *buf, 1);
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	if (!buf) return 1;
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	if (buf->len != len) {
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		buf->data = realloc(buf->data, len * sizeof(buf->data[0]));
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		if (len > buf->len) {
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			memset(&buf->data[buf->len], 0, len - buf->len);
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		} else {
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			if (buf->offset >= len) buf->offset = 0;
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		}
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		buf->len = len;
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	}
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	*bufp = buf;
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	return 0;
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}
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float foobuf_read(struct foobuf *buf, size_t offset)
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{
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	size_t len = buf->len;
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	return buf->data[((buf->offset - offset) + len) % len];
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}
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void foobuf_write(struct foobuf *buf, float val)
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{
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	if (!buf || !buf->data) return;
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	size_t offset = buf->offset;
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	buf->data[offset] = val;
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	offset++;
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	if (offset == buf->len) offset = 0;
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	buf->offset = offset;
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}
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