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cc193f1f0b
buffer_read_char can be used in place of buffer_read_string(1) to avoid consuming valuable static buffer space. The delta applier will use this to read variable-length integers one byte at a time. Underneath, it is fgetc, wrapped so the line_buffer library can maintain its role as gatekeeper of input. Later it might be worth checking if fgetc_unlocked is faster --- most line_buffer functions are not thread-safe anyway. Helpd-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
100 lines
2.3 KiB
C
100 lines
2.3 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 "strbuf.h"
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#define COPY_BUFFER_LEN 4096
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int buffer_init(struct line_buffer *buf, const char *filename)
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{
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buf->infile = filename ? fopen(filename, "r") : stdin;
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if (!buf->infile)
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return -1;
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return 0;
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}
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int buffer_deinit(struct line_buffer *buf)
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{
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int err;
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if (buf->infile == stdin)
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return ferror(buf->infile);
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err = ferror(buf->infile);
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err |= fclose(buf->infile);
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return err;
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}
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int buffer_read_char(struct line_buffer *buf)
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{
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return fgetc(buf->infile);
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}
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/* Read a line without trailing newline. */
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char *buffer_read_line(struct line_buffer *buf)
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{
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char *end;
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if (!fgets(buf->line_buffer, sizeof(buf->line_buffer), buf->infile))
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/* Error or data exhausted. */
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return NULL;
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end = buf->line_buffer + strlen(buf->line_buffer);
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if (end[-1] == '\n')
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end[-1] = '\0';
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else if (feof(buf->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 buf->line_buffer;
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}
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char *buffer_read_string(struct line_buffer *buf, uint32_t len)
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{
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strbuf_reset(&buf->blob_buffer);
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strbuf_fread(&buf->blob_buffer, len, buf->infile);
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return ferror(buf->infile) ? NULL : buf->blob_buffer.buf;
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}
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void buffer_read_binary(struct line_buffer *buf,
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struct strbuf *sb, uint32_t size)
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{
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strbuf_fread(sb, size, buf->infile);
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}
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void buffer_copy_bytes(struct line_buffer *buf, uint32_t len)
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{
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char byte_buffer[COPY_BUFFER_LEN];
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uint32_t in;
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while (len > 0 && !feof(buf->infile) && !ferror(buf->infile)) {
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in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
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in = fread(byte_buffer, 1, in, buf->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(buf, 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(struct line_buffer *buf, uint32_t len)
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{
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char byte_buffer[COPY_BUFFER_LEN];
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uint32_t in;
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while (len > 0 && !feof(buf->infile) && !ferror(buf->infile)) {
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in = len < COPY_BUFFER_LEN ? len : COPY_BUFFER_LEN;
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in = fread(byte_buffer, 1, in, buf->infile);
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len -= in;
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}
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}
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void buffer_reset(struct line_buffer *buf)
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{
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strbuf_release(&buf->blob_buffer);
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}
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