ccan/io: use explicit IO callback functions, instead of io_state values.

Explicit callbacks are slower, but more flexible.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/ccan/io/backend.h b/ccan/io/backend.h
index bc88c289b7bf412d8d12d46497e1f375616a8e72..86db8c3d1de44983e3061bb33699a7783d69c88d 100644 (file)
--- a/ccan/io/backend.h
+++ b/ccan/io/backend.h
@@ -21,15 +21,14 @@ struct io_listener {
        void *conn_arg;
 };
 
-enum io_state {
-       /* These wait for something to input */
-       READ,
-       READPART,
-
-       /* These wait for room to output */
-       WRITE,
-       WRITEPART,
+enum io_result {
+       RESULT_AGAIN,
+       RESULT_FINISHED,
+       RESULT_CLOSE
+};
 
+enum io_state {
+       IO,
        NEXT, /* eg starting, woken from idle, return from io_break. */
        IDLE,
        FINISHED,
@@ -82,6 +81,8 @@ struct io_conn {
        struct io_conn *duplex;
        struct io_timeout *timeout;
 
+       enum io_result (*io)(struct io_conn *conn);
+
        int pollflag; /* 0, POLLIN or POLLOUT */
        enum io_state state;
        union {

diff --git a/ccan/io/io.c b/ccan/io/io.c
index 150f7269a4428b9890319481dfb93532971304ba..84be1758330e61481638ce31d72826799089f81b 100644 (file)
--- a/ccan/io/io.c
+++ b/ccan/io/io.c
@@ -119,6 +119,20 @@ bool io_timeout_(struct io_conn *conn, struct timespec ts,
        return true;
 }
 
+static enum io_result do_write(struct io_conn *conn)
+{
+       ssize_t ret = write(conn->fd.fd, conn->u.write.buf, conn->u.write.len);
+       if (ret < 0)
+               return RESULT_CLOSE;
+
+       conn->u.write.buf += ret;
+       conn->u.write.len -= ret;
+       if (conn->u.write.len == 0)
+               return RESULT_FINISHED;
+       else
+               return RESULT_AGAIN;
+}
+
 /* Queue some data to be written. */
 struct io_plan *io_write_(struct io_conn *conn, const void *data, size_t len,
                          struct io_plan *(*cb)(struct io_conn *, void *),
@@ -126,10 +140,24 @@ struct io_plan *io_write_(struct io_conn *conn, const void *data, size_t len,
 {
        conn->u.write.buf = data;
        conn->u.write.len = len;
+       conn->io = do_write;
        conn->next = cb;
        conn->next_arg = arg;
        conn->pollflag = POLLOUT;
-       return to_ioplan(WRITE);
+       return to_ioplan(IO);
+}
+
+static enum io_result do_read(struct io_conn *conn)
+{
+       ssize_t ret = read(conn->fd.fd, conn->u.read.buf, conn->u.read.len);
+       if (ret <= 0)
+               return RESULT_CLOSE;
+       conn->u.read.buf += ret;
+       conn->u.read.len -= ret;
+       if (conn->u.read.len == 0)
+               return RESULT_FINISHED;
+       else
+               return RESULT_AGAIN;
 }
 
 /* Queue a request to read into a buffer. */
@@ -139,10 +167,21 @@ struct io_plan *io_read_(struct io_conn *conn, void *data, size_t len,
 {
        conn->u.read.buf = data;
        conn->u.read.len = len;
+       conn->io = do_read;
        conn->next = cb;
        conn->next_arg = arg;
        conn->pollflag = POLLIN;
-       return to_ioplan(READ);
+       return to_ioplan(IO);
+}
+
+static enum io_result do_read_partial(struct io_conn *conn)
+{
+       ssize_t ret = read(conn->fd.fd, conn->u.readpart.buf,
+                          *conn->u.readpart.lenp);
+       if (ret <= 0)
+               return RESULT_CLOSE;
+       *conn->u.readpart.lenp = ret;
+       return RESULT_FINISHED;
 }
 
 /* Queue a partial request to read into a buffer. */
@@ -152,10 +191,21 @@ struct io_plan *io_read_partial_(struct io_conn *conn, void *data, size_t *len,
 {
        conn->u.readpart.buf = data;
        conn->u.readpart.lenp = len;
+       conn->io = do_read_partial;
        conn->next = cb;
        conn->next_arg = arg;
        conn->pollflag = POLLIN;
-       return to_ioplan(READPART);
+       return to_ioplan(IO);
+}
+
+static enum io_result do_write_partial(struct io_conn *conn)
+{
+       ssize_t ret = write(conn->fd.fd, conn->u.writepart.buf,
+                           *conn->u.writepart.lenp);
+       if (ret < 0)
+               return RESULT_CLOSE;
+       *conn->u.writepart.lenp = ret;
+       return RESULT_FINISHED;
 }
 
 /* Queue a partial write request. */
@@ -166,10 +216,11 @@ struct io_plan *io_write_partial_(struct io_conn *conn,
 {
        conn->u.writepart.buf = data;
        conn->u.writepart.lenp = len;
+       conn->io = do_write_partial;
        conn->next = cb;
        conn->next_arg = arg;
        conn->pollflag = POLLOUT;
-       return to_ioplan(WRITEPART);
+       return to_ioplan(IO);
 }
 
 struct io_plan *io_idle(struct io_conn *conn)
@@ -200,50 +251,17 @@ static struct io_plan *do_next(struct io_conn *conn)
 
 struct io_plan *do_ready(struct io_conn *conn)
 {
-       ssize_t ret;
-       bool finished;
-
-       switch (conn->state) {
-       case WRITE:
-               ret = write(conn->fd.fd, conn->u.write.buf, conn->u.write.len);
-               if (ret < 0)
-                       return io_close(conn, NULL);
-               conn->u.write.buf += ret;
-               conn->u.write.len -= ret;
-               finished = (conn->u.write.len == 0);
-               break;
-       case WRITEPART:
-               ret = write(conn->fd.fd, conn->u.writepart.buf,
-                           *conn->u.writepart.lenp);
-               if (ret < 0)
-                       return io_close(conn, NULL);
-               *conn->u.writepart.lenp = ret;
-               finished = true;
-               break;
-       case READ:
-               ret = read(conn->fd.fd, conn->u.read.buf, conn->u.read.len);
-               if (ret <= 0)
-                       return io_close(conn, NULL);
-               conn->u.read.buf += ret;
-               conn->u.read.len -= ret;
-               finished = (conn->u.read.len == 0);
-               break;
-       case READPART:
-               ret = read(conn->fd.fd, conn->u.readpart.buf,
-                           *conn->u.readpart.lenp);
-               if (ret <= 0)
-                       return io_close(conn, NULL);
-               *conn->u.readpart.lenp = ret;
-               finished = true;
-               break;
+       assert(conn->state == IO);
+       switch (conn->io(conn)) {
+       case RESULT_CLOSE:
+               return io_close(conn, NULL);
+       case RESULT_FINISHED:
+               return do_next(conn);
+       case RESULT_AGAIN:
+               return to_ioplan(conn->state);
        default:
-               /* Shouldn't happen. */
                abort();
        }
-
-       if (finished)
-               return do_next(conn);
-       return to_ioplan(conn->state);
 }
 
 /* Useful next functions. */

diff --git a/ccan/io/test/run-06-idle.c b/ccan/io/test/run-06-idle.c
index acf372f56fe0a287898af6dfc269c497318222bc..597060c2b596f80b5a3b5a43e3539f3371a7fa01 100644 (file)
--- a/ccan/io/test/run-06-idle.c
+++ b/ccan/io/test/run-06-idle.c
@@ -16,7 +16,7 @@ struct data {
        char buf[4];
 };
 
-static struct io_plan *do_read(struct io_conn *conn, struct data *d)
+static struct io_plan *plan_read(struct io_conn *conn, struct data *d)
 {
        ok1(d->state == 2 || d->state == 3);
        d->state++;
@@ -28,7 +28,7 @@ static struct io_plan *start_waker(struct io_conn *conn, struct data *d)
        ok1(d->state == 1);
        d->state++;
 
-       io_wake(idler, do_read, d);
+       io_wake(idler, plan_read, d);
        return io_close(conn, NULL);
 }
 

diff --git a/ccan/io/test/run-07-break.c b/ccan/io/test/run-07-break.c
index 327fa956da687571d92eaf824120cba7531bce51..3dac4ecee2d9e6c0af85c07ce5eb3f1322cae67c 100644 (file)
--- a/ccan/io/test/run-07-break.c
+++ b/ccan/io/test/run-07-break.c
@@ -11,7 +11,7 @@ struct data {
        char buf[4];
 };
 
-static struct io_plan *do_read(struct io_conn *conn, struct data *d)
+static struct io_plan *plan_read(struct io_conn *conn, struct data *d)
 {
        ok1(d->state == 1);
        d->state++;
@@ -22,7 +22,7 @@ static struct io_plan *start_break(struct io_conn *conn, struct data *d)
 {
        ok1(d->state == 0);
        d->state++;
-       return io_break(conn, d, do_read, d);
+       return io_break(conn, d, plan_read, d);
 }
 
 static void finish_ok(struct io_conn *conn, struct data *d)

diff --git a/ccan/io/test/run-10-many.c b/ccan/io/test/run-10-many.c
index b20b2285b9e9621673ba7f3318834d9ea191a8c9..313691187f6c63d059f03f0144e5a1fa6f2c48be 100644 (file)
--- a/ccan/io/test/run-10-many.c
+++ b/ccan/io/test/run-10-many.c
@@ -18,7 +18,7 @@ struct buffer {
 static struct io_plan *poke_writer(struct io_conn *conn, struct buffer *buf);
 static struct io_plan *poke_reader(struct io_conn *conn, struct buffer *buf);
 
-static struct io_plan *do_read(struct io_conn *conn, struct buffer *buf)
+static struct io_plan *plan_read(struct io_conn *conn, struct buffer *buf)
 {
        assert(conn == buf->reader);
 
@@ -26,7 +26,7 @@ static struct io_plan *do_read(struct io_conn *conn, struct buffer *buf)
                       poke_writer, buf);
 }
 
-static struct io_plan *do_write(struct io_conn *conn, struct buffer *buf)
+static struct io_plan *plan_write(struct io_conn *conn, struct buffer *buf)
 {
        assert(conn == buf->writer);
 
@@ -42,7 +42,7 @@ static struct io_plan *poke_writer(struct io_conn *conn, struct buffer *buf)
                return io_close(conn, NULL);
 
        /* You write. */
-       io_wake(buf->writer, do_write, buf);
+       io_wake(buf->writer, plan_write, buf);
 
        /* I'll wait until you wake me. */
        return io_idle(conn);
@@ -52,7 +52,7 @@ static struct io_plan *poke_reader(struct io_conn *conn, struct buffer *buf)
 {
        assert(conn == buf->writer);
        /* You read. */
-       io_wake(buf->reader, do_read, buf);
+       io_wake(buf->reader, plan_read, buf);
 
        if (++buf->iters == NUM_ITERS)
                return io_close(conn, NULL);
@@ -91,7 +91,7 @@ int main(void)
                buf[i].reader = io_new_conn(last_read, reader, NULL, &buf[i]);
                if (!buf[i].reader)
                        break;
-               buf[i].writer = io_new_conn(fds[1], do_write, NULL, &buf[i]);
+               buf[i].writer = io_new_conn(fds[1], plan_write, NULL, &buf[i]);
                if (!buf[i].writer)
                        break;
                last_read = fds[0];
@@ -104,7 +104,7 @@ int main(void)
        sprintf(buf[i].buf, "%i-%i", i, i);
        buf[i].reader = io_new_conn(last_read, reader, NULL, &buf[i]);
        ok1(buf[i].reader);
-       buf[i].writer = io_new_conn(last_write, do_write, NULL, &buf[i]);
+       buf[i].writer = io_new_conn(last_write, plan_write, NULL, &buf[i]);
        ok1(buf[i].writer);
 
        /* They should eventually exit */