connection: Factor out circular buffer functionality
This commit is contained in:
Kristian Høgsberg
parent
4363d2aa4d
commit
d6f4da7927
219
connection.c
219
connection.c
@ -43,6 +43,8 @@ struct wl_buffer {
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int head, tail;
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};
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#define MASK(i) ((i) & 4095)
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struct wl_connection {
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struct wl_buffer in, out;
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int fd;
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@ -50,6 +52,86 @@ struct wl_connection {
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wl_connection_update_func_t update;
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};
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static void
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wl_buffer_put(struct wl_buffer *b, const void *data, size_t count)
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{
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int head, size;
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head = MASK(b->head);
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if (head + count <= sizeof b->data) {
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memcpy(b->data + head, data, count);
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} else {
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size = sizeof b->data - head;
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memcpy(b->data + head, data, size);
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memcpy(b->data, (const char *) data + size, count - size);
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}
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b->head += count;
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}
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static void
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wl_buffer_put_iov(struct wl_buffer *b, struct iovec *iov, int *count)
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{
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int head, tail;
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head = MASK(b->head);
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tail = MASK(b->tail);
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if (head < tail) {
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iov[0].iov_base = b->data + head;
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iov[0].iov_len = tail - head;
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*count = 1;
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} else if (tail == 0) {
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iov[0].iov_base = b->data + head;
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iov[0].iov_len = sizeof b->data - head;
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*count = 1;
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} else {
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iov[0].iov_base = b->data + head;
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iov[0].iov_len = sizeof b->data - head;
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iov[1].iov_base = b->data;
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iov[1].iov_len = tail;
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*count = 2;
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}
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}
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static void
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wl_buffer_get_iov(struct wl_buffer *b, struct iovec *iov, int *count)
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{
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int head, tail;
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head = MASK(b->head);
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tail = MASK(b->tail);
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if (tail < head) {
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iov[0].iov_base = b->data + tail;
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iov[0].iov_len = head - tail;
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*count = 1;
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} else if (head == 0) {
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iov[0].iov_base = b->data + tail;
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iov[0].iov_len = sizeof b->data - tail;
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*count = 1;
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} else {
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iov[0].iov_base = b->data + tail;
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iov[0].iov_len = sizeof b->data - tail;
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iov[1].iov_base = b->data;
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iov[1].iov_len = head;
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*count = 2;
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}
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}
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static void
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wl_buffer_copy(struct wl_buffer *b, void *data, size_t count)
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{
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int tail, size;
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tail = MASK(b->tail);
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if (tail + count <= sizeof b->data) {
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memcpy(data, b->data + tail, count);
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} else {
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size = sizeof b->data - tail;
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memcpy(data, b->data + tail, size);
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memcpy((char *) data + size, b->data, count - size);
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}
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}
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struct wl_connection *
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wl_connection_create(int fd,
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wl_connection_update_func_t update,
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@ -80,67 +162,35 @@ wl_connection_destroy(struct wl_connection *connection)
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void
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wl_connection_copy(struct wl_connection *connection, void *data, size_t size)
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{
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struct wl_buffer *b;
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int tail, rest;
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b = &connection->in;
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tail = b->tail;
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if (tail + size <= ARRAY_LENGTH(b->data)) {
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memcpy(data, b->data + tail, size);
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} else {
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rest = ARRAY_LENGTH(b->data) - tail;
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memcpy(data, b->data + tail, rest);
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memcpy(data + rest, b->data, size - rest);
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}
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wl_buffer_copy(&connection->in, data, size);
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}
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void
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wl_connection_consume(struct wl_connection *connection, size_t size)
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{
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struct wl_buffer *b;
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int tail, rest;
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b = &connection->in;
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tail = b->tail;
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if (tail + size <= ARRAY_LENGTH(b->data)) {
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b->tail += size;
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} else {
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rest = ARRAY_LENGTH(b->data) - tail;
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b->tail = size - rest;
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}
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connection->in.tail += size;
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}
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int wl_connection_data(struct wl_connection *connection, uint32_t mask)
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{
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struct wl_buffer *b;
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struct iovec iov[2];
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struct msghdr msg;
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int len, head, tail, count, size, available;
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int len, count;
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if (mask & WL_CONNECTION_READABLE) {
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b = &connection->in;
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head = connection->in.head;
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if (head < b->tail) {
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iov[0].iov_base = b->data + head;
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iov[0].iov_len = b->tail - head;
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count = 1;
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} else {
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size = ARRAY_LENGTH(b->data) - head;
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iov[0].iov_base = b->data + head;
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iov[0].iov_len = size;
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iov[1].iov_base = b->data;
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iov[1].iov_len = b->tail;
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count = 2;
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}
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wl_buffer_put_iov(&connection->in, iov, &count);
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msg.msg_name = NULL;
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msg.msg_namelen = 0;
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msg.msg_iov = iov;
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msg.msg_iovlen = count;
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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do {
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msg.msg_name = NULL;
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msg.msg_namelen = 0;
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msg.msg_iov = iov;
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msg.msg_iovlen = count;
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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len = recvmsg(connection->fd, &msg, 0);
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} while (len < 0 && errno == EINTR);
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if (len < 0) {
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fprintf(stderr,
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"read error from connection %p: %m (%d)\n",
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@ -149,90 +199,47 @@ int wl_connection_data(struct wl_connection *connection, uint32_t mask)
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} else if (len == 0) {
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/* FIXME: Handle this better? */
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return -1;
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} else if (head + len <= ARRAY_LENGTH(b->data)) {
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b->head += len;
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} else {
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b->head = head + len - ARRAY_LENGTH(b->data);
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}
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/* We know we have data in the buffer at this point,
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* so if head equals tail, it means the buffer is
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* full. */
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available = b->head - b->tail;
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if (available == 0)
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available = sizeof b->data;
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else if (available < 0)
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available += ARRAY_LENGTH(b->data);
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} else {
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available = 0;
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connection->in.head += len;
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}
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if (mask & WL_CONNECTION_WRITABLE) {
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b = &connection->out;
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tail = b->tail;
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if (tail < b->head) {
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iov[0].iov_base = b->data + tail;
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iov[0].iov_len = b->head - tail;
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count = 1;
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} else {
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size = ARRAY_LENGTH(b->data) - tail;
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iov[0].iov_base = b->data + tail;
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iov[0].iov_len = size;
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iov[1].iov_base = b->data;
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iov[1].iov_len = b->head;
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count = 2;
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}
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wl_buffer_get_iov(&connection->out, iov, &count);
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msg.msg_name = NULL;
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msg.msg_namelen = 0;
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msg.msg_iov = iov;
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msg.msg_iovlen = count;
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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do {
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msg.msg_name = NULL;
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msg.msg_namelen = 0;
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msg.msg_iov = iov;
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msg.msg_iovlen = count;
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msg.msg_control = NULL;
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msg.msg_controllen = 0;
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len = sendmsg(connection->fd, &msg, 0);
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} while (len < 0 && errno == EINTR);
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if (len < 0) {
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fprintf(stderr, "write error for connection %p: %m\n", connection);
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return -1;
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} else if (tail + len <= ARRAY_LENGTH(b->data)) {
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b->tail += len;
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} else {
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b->tail = tail + len - ARRAY_LENGTH(b->data);
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}
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/* We just took data out of the buffer, so at this
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* point if head equals tail, the buffer is empty. */
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if (b->tail == b->head)
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connection->out.tail += len;
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if (connection->out.tail == connection->out.head)
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connection->update(connection,
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WL_CONNECTION_READABLE,
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connection->data);
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}
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return available;
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return connection->in.head - connection->in.tail;
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}
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void
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wl_connection_write(struct wl_connection *connection, const void *data, size_t count)
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wl_connection_write(struct wl_connection *connection,
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const void *data, size_t count)
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{
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struct wl_buffer *b;
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size_t size;
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int head;
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wl_buffer_put(&connection->out, data, count);
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b = &connection->out;
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head = b->head;
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if (head + count <= ARRAY_LENGTH(b->data)) {
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memcpy(b->data + head, data, count);
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b->head += count;
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} else {
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size = ARRAY_LENGTH(b->data) - head;
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memcpy(b->data + head, data, size);
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memcpy(b->data, data + size, count - size);
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b->head = count - size;
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}
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if (b->tail == head)
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if (connection->out.head - connection->out.tail == count)
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connection->update(connection,
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WL_CONNECTION_READABLE |
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WL_CONNECTION_WRITABLE,
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