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/*
Line based I/O over fds
Copyright (C) Amitay Isaacs 2018
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include <talloc.h>
#include "lib/util/sys_rw.h"
#include "common/line.h"
struct line_read_state {
line_process_fn_t callback;
void *private_data;
char *buf;
size_t hint, len, offset;
int num_lines;
};
static bool line_read_one(char *buf, size_t start, size_t len, size_t *pos)
{
size_t i;
for (i=start; i<len; i++) {
if (buf[i] == '\n' || buf[i] == '\0') {
*pos = i;
return true;
}
}
return false;
}
static int line_read_process(struct line_read_state *state)
{
size_t start = 0;
size_t pos = 0;
while (1) {
int ret;
bool ok;
ok = line_read_one(state->buf, start, state->offset, &pos);
if (! ok) {
break;
}
state->buf[pos] = '\0';
state->num_lines += 1;
ret = state->callback(state->buf + start, state->private_data);
if (ret != 0) {
return ret;
}
start = pos+1;
}
if (pos > 0) {
if (pos+1 < state->offset) {
memmove(state->buf,
state->buf + pos+1,
state->offset - (pos+1));
}
state->offset -= (pos+1);
}
return 0;
}
int line_read(int fd,
size_t length,
TALLOC_CTX *mem_ctx,
line_process_fn_t callback,
void *private_data,
int *num_lines)
{
struct line_read_state state;
if (length < 32) {
length = 32;
}
state = (struct line_read_state) {
.callback = callback,
.private_data = private_data,
.hint = length,
};
while (1) {
ssize_t n;
int ret;
if (state.offset == state.len) {
state.len += state.hint;
state.buf = talloc_realloc_size(mem_ctx,
state.buf,
state.len);
if (state.buf == NULL) {
return ENOMEM;
}
}
n = sys_read(fd,
state.buf + state.offset,
state.len - state.offset);
if (n < 0) {
return errno;
}
if (n == 0) {
break;
}
state.offset += n;
ret = line_read_process(&state);
if (ret != 0) {
if (num_lines != NULL) {
*num_lines = state.num_lines;
}
return ret;
}
}
if (num_lines != NULL) {
*num_lines = state.num_lines;
}
return 0;
}
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