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/*
Simple queuing of input and output records for libctdb
Copyright (C) Rusty Russell 2010
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 <sys/types.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include "io_elem.h"
#include <tdb.h>
#include <ctdb_protocol.h> // For CTDB_DS_ALIGNMENT and ctdb_req_header
struct io_elem {
size_t len, off;
char *data;
};
struct io_elem *new_io_elem(size_t len)
{
struct io_elem *elem;
size_t ask = len;
len = (len + (CTDB_DS_ALIGNMENT-1)) & ~(CTDB_DS_ALIGNMENT-1);
elem = malloc(sizeof(*elem));
if (!elem)
return NULL;
elem->data = malloc(len);
if (!elem->data) {
free(elem);
return NULL;
}
/* stamp out any padding to keep valgrind happy */
if (ask != len) {
memset(elem->data + ask, 0, len-ask);
}
elem->len = len;
elem->off = 0;
return elem;
}
void free_io_elem(struct io_elem *io)
{
free(io->data);
free(io);
}
bool io_elem_finished(const struct io_elem *io)
{
return io->off == io->len;
}
void io_elem_init_req_header(struct io_elem *io,
uint32_t operation,
uint32_t destnode,
uint32_t reqid)
{
struct ctdb_req_header *hdr = io_elem_data(io, NULL);
hdr->length = io->len;
hdr->ctdb_magic = CTDB_MAGIC;
hdr->ctdb_version = CTDB_VERSION;
/* Generation and srcnode only used for inter-ctdbd communication. */
hdr->generation = 0;
hdr->destnode = destnode;
hdr->srcnode = 0;
hdr->operation = operation;
hdr->reqid = reqid;
}
/* Access to raw data: if len is non-NULL it is filled in. */
void *io_elem_data(const struct io_elem *io, size_t *len)
{
if (len)
*len = io->len;
return io->data;
}
/* Returns -1 if we hit an error. Errno will be set. */
int read_io_elem(int fd, struct io_elem *io)
{
ssize_t ret;
ret = read(fd, io->data + io->off, io->len - io->off);
if (ret < 0)
return ret;
io->off += ret;
if (io_elem_finished(io)) {
struct ctdb_req_header *hdr = (void *)io->data;
/* Finished. But maybe this was just header? */
if (io->len == sizeof(*hdr) && hdr->length > io->len) {
int reret;
void *newdata;
/* Enlarge and re-read. */
io->len = hdr->length;
newdata = realloc(io->data, io->len);
if (!newdata)
return -1;
io->data = newdata;
/* Try reading again immediately. */
reret = read_io_elem(fd, io);
if (reret >= 0)
reret += ret;
return reret;
}
}
return ret;
}
/* Returns -1 if we hit an error. Errno will be set. */
int write_io_elem(int fd, struct io_elem *io)
{
ssize_t ret;
ret = write(fd, io->data + io->off, io->len - io->off);
if (ret < 0)
return ret;
io->off += ret;
return ret;
}
void io_elem_reset(struct io_elem *io)
{
io->off = 0;
}
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