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#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <sys/uio.h>
#include "connection.h"
#define ARRAY_LENGTH(a) (sizeof (a) / sizeof (a)[0])
struct wl_buffer {
char data[4096];
int head, tail;
};
struct wl_connection {
struct wl_buffer in, out;
int fd;
void *data;
wl_connection_update_func_t update;
};
struct wl_connection *
wl_connection_create(int fd,
wl_connection_update_func_t update,
void *data)
{
struct wl_connection *connection;
connection = malloc(sizeof *connection);
memset(connection, 0, sizeof *connection);
connection->fd = fd;
connection->update = update;
connection->data = data;
connection->update(connection,
WL_CONNECTION_READABLE,
connection->data);
return connection;
}
void
wl_connection_destroy(struct wl_connection *connection)
{
free(connection);
}
void
wl_connection_copy(struct wl_connection *connection, void *data, size_t size)
{
struct wl_buffer *b;
int tail, rest;
b = &connection->in;
tail = b->tail;
if (tail + size <= ARRAY_LENGTH(b->data)) {
memcpy(data, b->data + tail, size);
} else {
rest = ARRAY_LENGTH(b->data) - tail;
memcpy(data, b->data + tail, rest);
memcpy(data + rest, b->data, size - rest);
}
}
void
wl_connection_consume(struct wl_connection *connection, size_t size)
{
struct wl_buffer *b;
int tail, rest;
b = &connection->in;
tail = b->tail;
if (tail + size <= ARRAY_LENGTH(b->data)) {
b->tail += size;
} else {
rest = ARRAY_LENGTH(b->data) - tail;
b->tail = size - rest;
}
}
int wl_connection_data(struct wl_connection *connection, uint32_t mask)
{
struct wl_buffer *b;
struct iovec iov[2];
int len, head, tail, count, size, available;
if (mask & WL_CONNECTION_READABLE) {
b = &connection->in;
head = connection->in.head;
if (head < b->tail) {
iov[0].iov_base = b->data + head;
iov[0].iov_len = b->tail - head;
count = 1;
} else {
size = ARRAY_LENGTH(b->data) - head;
iov[0].iov_base = b->data + head;
iov[0].iov_len = size;
iov[1].iov_base = b->data;
iov[1].iov_len = b->tail;
count = 2;
}
len = readv(connection->fd, iov, count);
if (len < 0) {
fprintf(stderr,
"read error from connection %p: %m (%d)\n",
connection, errno);
return -1;
} else if (len == 0) {
/* FIXME: Handle this better? */
return -1;
} else if (head + len <= ARRAY_LENGTH(b->data)) {
b->head += len;
} else {
b->head = head + len - ARRAY_LENGTH(b->data);
}
/* We know we have data in the buffer at this point,
* so if head equals tail, it means the buffer is
* full. */
available = b->head - b->tail;
if (available == 0)
available = sizeof b->data;
else if (available < 0)
available += ARRAY_LENGTH(b->data);
} else {
available = 0;
}
if (mask & WL_CONNECTION_WRITABLE) {
b = &connection->out;
tail = b->tail;
if (tail < b->head) {
iov[0].iov_base = b->data + tail;
iov[0].iov_len = b->head - tail;
count = 1;
} else {
size = ARRAY_LENGTH(b->data) - tail;
iov[0].iov_base = b->data + tail;
iov[0].iov_len = size;
iov[1].iov_base = b->data;
iov[1].iov_len = b->head;
count = 2;
}
len = writev(connection->fd, iov, count);
if (len < 0) {
fprintf(stderr, "write error for connection %p: %m\n", connection);
return -1;
} else if (tail + len <= ARRAY_LENGTH(b->data)) {
b->tail += len;
} else {
b->tail = tail + len - ARRAY_LENGTH(b->data);
}
/* We just took data out of the buffer, so at this
* point if head equals tail, the buffer is empty. */
if (b->tail == b->head)
connection->update(connection,
WL_CONNECTION_READABLE,
connection->data);
}
return available;
}
void
wl_connection_write(struct wl_connection *connection, const void *data, size_t count)
{
struct wl_buffer *b;
size_t size;
int head;
b = &connection->out;
head = b->head;
if (head + count <= ARRAY_LENGTH(b->data)) {
memcpy(b->data + head, data, count);
b->head += count;
} else {
size = ARRAY_LENGTH(b->data) - head;
memcpy(b->data + head, data, size);
memcpy(b->data, data + size, count - size);
b->head = count - size;
}
if (b->tail == head)
connection->update(connection,
WL_CONNECTION_READABLE |
WL_CONNECTION_WRITABLE,
connection->data);
}
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