47 lines
794 B
C
47 lines
794 B
C
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/*
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* Copyright (c) 2026, Chloe M.
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* Provided under the BSD-3 clause
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*/
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#include <stdint.h>
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#include <stddef.h>
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#include <errno.h>
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#include <unistd.h>
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#include "cescal/readbuf.h"
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int
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readbuf_init(struct readbuf *rb)
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{
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if (rb == NULL) {
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errno = EINVAL;
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return -1;
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}
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rb->size = 0;
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rb->tail = 0;
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return 0;
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}
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char
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readbuf_read(struct readbuf *rb, int fd)
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{
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ssize_t nread = -1;
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if (rb == NULL || fd < 0) {
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errno = EINVAL;
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return '\0';
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}
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#define N_RESIDUAL(rb) ((rb)->size - (rb)->tail)
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if (N_RESIDUAL(rb) == 0 || rb->size == 0) {
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if ((nread = read(fd, rb->buf, READBUF_CAP)) <= 0)
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return nread;
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rb->size = nread;
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rb->tail = 0;
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}
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#undef N_RESIDUAL
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return rb->buf[rb->tail++];
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}
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