mirror of
https://github.com/fluencelabs/musl
synced 2025-06-08 04:21:39 +00:00
39 lines
940 B
C
39 lines
940 B
C
#include "stdio_impl.h"
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int __underflow(FILE *f)
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{
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ssize_t cnt;
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/* Read from buffer (Do we ever get called when this is true??) */
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if (f->rpos < f->rstop) return *f->rpos;
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/* Initialize if we're not already reading */
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if (!f->rstop) {
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/* Fail immediately if unreadable, eof, or error state. */
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if (f->flags & (F_EOF|F_ERR|F_NORD)) return EOF;
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/* Set byte orientation -1,0=>-1; 1=>1 */
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f->mode |= f->mode-1;
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/* Flush any unwritten output; fail on error. */
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if (f->wpos > f->buf && __oflow(f)) return EOF;
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/* Disallow writes to buffer. */
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f->wstop = 0;
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}
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/* Perform the underlying read operation */
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if ((cnt=f->read(f, f->buf, f->buf_size)) + 1 <= 1) {
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/* Set flags and leave read mode */
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f->flags |= F_EOF | (cnt & F_ERR);
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f->rpos = f->rend = f->rstop = 0;
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return EOF;
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}
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/* Setup buffer pointers for reading from buffer */
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f->rpos = f->buf;
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f->rend = f->rstop = f->buf + cnt;
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return *f->rpos;
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}
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