ccan/io: simplify I/O callbacks.

Use a -1 for error codes.  This makes it easier to write your own io funcs.

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

diff --git a/ccan/io/io.c b/ccan/io/io.c
index 70e4f1b5037cff62493baee8b1adc7c6faaaae22..1c0af6b97e05f0ac6018c0cc7cba7fa1e0ef08a9 100644 (file)
--- a/ccan/io/io.c
+++ b/ccan/io/io.c
@@ -151,14 +151,11 @@ bool io_timeout_(struct io_conn *conn, struct timespec ts,
 }
 
 /* Returns true if we're finished. */
-static bool do_write(int fd, struct io_plan *plan)
+static int do_write(int fd, struct io_plan *plan)
 {
        ssize_t ret = write(fd, plan->u.write.buf, plan->u.write.len);
-       if (ret < 0) {
-               /* Override next function to close us. */
-               plan->next = io_close;
-               return true;
-       }
+       if (ret < 0)
+               return -1;
 
        plan->u.write.buf += ret;
        plan->u.write.len -= ret;
@@ -184,14 +181,11 @@ struct io_plan io_write_(const void *data, size_t len,
        return plan;
 }
 
-static bool do_read(int fd, struct io_plan *plan)
+static int do_read(int fd, struct io_plan *plan)
 {
        ssize_t ret = read(fd, plan->u.read.buf, plan->u.read.len);
-       if (ret <= 0) {
-               /* Override next function to close us. */
-               plan->next = io_close;
-               return true;
-       }
+       if (ret <= 0)
+               return -1;
 
        plan->u.read.buf += ret;
        plan->u.read.len -= ret;
@@ -217,17 +211,14 @@ struct io_plan io_read_(void *data, size_t len,
        return plan;
 }
 
-static bool do_read_partial(int fd, struct io_plan *plan)
+static int do_read_partial(int fd, struct io_plan *plan)
 {
        ssize_t ret = read(fd, plan->u.readpart.buf, *plan->u.readpart.lenp);
-       if (ret <= 0) {
-               /* Override next function to close us. */
-               plan->next = io_close;
-               return true;
-       }
+       if (ret <= 0)
+               return -1;
 
        *plan->u.readpart.lenp = ret;
-       return true;
+       return 1;
 }
 
 /* Queue a partial request to read into a buffer. */
@@ -249,17 +240,14 @@ struct io_plan io_read_partial_(void *data, size_t *len,
        return plan;
 }
 
-static bool do_write_partial(int fd, struct io_plan *plan)
+static int do_write_partial(int fd, struct io_plan *plan)
 {
        ssize_t ret = write(fd, plan->u.writepart.buf, *plan->u.writepart.lenp);
-       if (ret < 0) {
-               /* Override next function to close us. */
-               plan->next = io_close;
-               return true;
-       }
+       if (ret < 0)
+               return -1;
 
        *plan->u.writepart.lenp = ret;
-       return true;
+       return 1;
 }
 
 /* Queue a partial write request. */
@@ -310,7 +298,16 @@ void io_wake_(struct io_conn *conn, struct io_plan plan)
 
 void io_ready(struct io_conn *conn)
 {
-       if (conn->plan.io(conn->fd.fd, &conn->plan)) {
+       switch (conn->plan.io(conn->fd.fd, &conn->plan)) {
+       case -1: /* Failure means a new plan: close up. */
+               set_current(conn);
+               conn->plan = io_close(NULL, NULL);
+               backend_plan_changed(conn);
+               set_current(NULL);
+               break;
+       case 0: /* Keep going with plan. */
+               break;
+       case 1: /* Done: get next plan. */
                set_current(conn);
                if (timeout_active(conn))
                        backend_del_timeout(conn);

diff --git a/ccan/io/io.h b/ccan/io/io.h
index 5820f87750059ebf3fd9a1bfaaac14a0bbc51df8..105a90825dcea8caf53cdb1ec1ce25890acdf53e 100644 (file)
--- a/ccan/io/io.h
+++ b/ccan/io/io.h
@@ -16,7 +16,7 @@ struct io_conn;
 struct io_plan {
        int pollflag;
        /* Only NULL if idle. */
-       bool (*io)(int fd, struct io_plan *plan);
+       int (*io)(int fd, struct io_plan *plan);
        /* Only NULL if closing. */
        struct io_plan (*next)(struct io_conn *, void *arg);
        void *next_arg;

diff --git a/ccan/io/test/run-17-homemade-io.c b/ccan/io/test/run-17-homemade-io.c
index 8b6f17ad89a6ef21ad292cbf2b6c49317f51028d..de7ce7510d9915e4c2637a5e1dfb06b62aa773cb 100644 (file)
--- a/ccan/io/test/run-17-homemade-io.c
+++ b/ccan/io/test/run-17-homemade-io.c
@@ -23,7 +23,7 @@ static void finish_ok(struct io_conn *conn, struct packet *pkt)
        io_break(pkt, io_idle());
 }
 
-static bool do_read_packet(int fd, struct io_plan *plan)
+static int do_read_packet(int fd, struct io_plan *plan)
 {
        struct packet *pkt = plan->u.ptr_len.p;
        char *dest;
@@ -41,7 +41,7 @@ static bool do_read_packet(int fd, struct io_plan *plan)
                ok1(pkt->state == 2);
                pkt->state++;
                if (pkt->len == 0)
-                       return true;
+                       return 1;
                if (!pkt->contents && !(pkt->contents = malloc(pkt->len)))
                        goto fail;
                else {
@@ -63,9 +63,7 @@ static bool do_read_packet(int fd, struct io_plan *plan)
 
 fail:
        free(pkt->contents);
-       /* Override next function to close us. */
-       plan->next = io_close;
-       return true;
+       return -1;
 }
 
 static struct io_plan io_read_packet(struct packet *pkt,