3bbaec00a8
This library provides thread-unsafe fgets()- and fread()-like functions where the caller does not have to supply a buffer. It maintains a couple of static buffers and provides an API to use them. [rr: allow input from files other than stdin] [jn: with tests, documentation, and error handling improvements] Signed-off-by: David Barr <david.barr@cordelta.com> Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
98 lines
2.0 KiB
C
98 lines
2.0 KiB
C
/*
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* Licensed under a two-clause BSD-style license.
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* See LICENSE for details.
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*/
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#include "git-compat-util.h"
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#include "line_buffer.h"
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#include "obj_pool.h"
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#define LINE_BUFFER_LEN 10000
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#define COPY_BUFFER_LEN 4096
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/* Create memory pool for char sequence of known length */
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obj_pool_gen(blob, char, 4096)
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static char line_buffer[LINE_BUFFER_LEN];
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static char byte_buffer[COPY_BUFFER_LEN];
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static FILE *infile;
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int buffer_init(const char *filename)
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{
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infile = filename ? fopen(filename, "r") : stdin;
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if (!infile)
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return -1;
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return 0;
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}
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int buffer_deinit(void)
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{
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int err;
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if (infile == stdin)
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return ferror(infile);
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err = ferror(infile);
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err |= fclose(infile);
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return err;
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}
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/* Read a line without trailing newline. */
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char *buffer_read_line(void)
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{
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char *end;
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if (!fgets(line_buffer, sizeof(line_buffer), infile))
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/* Error or data exhausted. */
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return NULL;
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end = line_buffer + strlen(line_buffer);
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if (end[-1] == '\n')
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end[-1] = '\0';
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else if (feof(infile))
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; /* No newline at end of file. That's fine. */
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else
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/*
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* Line was too long.
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* There is probably a saner way to deal with this,
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* but for now let's return an error.
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*/
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return NULL;
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return line_buffer;
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}
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char *buffer_read_string(uint32_t len)
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{
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char *s;
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blob_free(blob_pool.size);
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s = blob_pointer(blob_alloc(len + 1));
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s[fread(s, 1, len, infile)] = '\0';
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return ferror(infile) ? NULL : s;
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}
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void buffer_copy_bytes(uint32_t len)
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{
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uint32_t in;
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while (len > 0 && !feof(infile) && !ferror(infile)) {
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in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
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in = fread(byte_buffer, 1, in, infile);
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len -= in;
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fwrite(byte_buffer, 1, in, stdout);
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if (ferror(stdout)) {
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buffer_skip_bytes(len);
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return;
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}
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}
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}
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void buffer_skip_bytes(uint32_t len)
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{
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uint32_t in;
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while (len > 0 && !feof(infile) && !ferror(infile)) {
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in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
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in = fread(byte_buffer, 1, in, infile);
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len -= in;
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}
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}
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void buffer_reset(void)
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{
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blob_reset();
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}
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