avoid copy by using iovecs

diff --git a/commands.c b/commands.c
index 446d92d..ffcd918 100644 (file)
--- a/commands.c
+++ b/commands.c
@@ -533,9 +533,15 @@ struct cmd_sendmsg_result {
 static void cmd_sendmsg_parsed(void *parsed_result, void *data)
 {
        struct cmd_sendmsg_result *res = parsed_result;
+       struct xbee_msg msg;
 
        (void)data;
-       xbeeapp_send_msg(res->addr, res->data, strlen(res->data), 1);
+
+       msg.iovlen = 1;
+       msg.iov[0].buf = res->data;
+       msg.iov[0].len = strlen(res->data);
+
+       xbeeapp_send_msg(res->addr, &msg, 1);
 }
 
 const char PROGMEM str_sendmsg[] = "sendmsg";
@@ -676,9 +682,15 @@ struct cmd_sendmsg_name_result {
 static void cmd_sendmsg_name_parsed(void *parsed_result, void *data)
 {
        struct cmd_sendmsg_name_result *res = parsed_result;
+       struct xbee_msg msg;
 
        (void)data;
-       xbeeapp_send_msg(res->neigh->addr, res->data, strlen(res->data), 1);
+
+       msg.iovlen = 1;
+       msg.iov[0].buf = res->data;
+       msg.iov[0].len = strlen(res->data);
+
+       xbeeapp_send_msg(res->neigh->addr, &msg, 1);
 }
 
 const parse_token_string_t PROGMEM cmd_sendmsg_name_sendmsg_name =

diff --git a/rc_proto.c b/rc_proto.c
index 22b6f28..56e8ad6 100644 (file)
--- a/rc_proto.c
+++ b/rc_proto.c
@@ -78,22 +78,21 @@ void rc_proto_rx_power_probe(int power_level)
 }
 
 /* send a hello message */
-// XXX iovec for xbee ?
 int8_t rc_proto_send_hello(uint64_t addr, void *data, uint8_t data_len)
 {
-       struct {
-               struct rc_proto_echo_req hdr;
-               char buf[XBEE_MAX_FRAME_LEN - sizeof(struct rc_proto_echo_req)];
-       } frame;
+       struct rc_proto_echo_req hdr;
+       struct xbee_msg msg;
 
-       if (data_len > sizeof(frame.buf))
-               return -1;
+       hdr.type = RC_PROTO_HELLO;
+       hdr.datalen = data_len;
+
+       msg.iovlen = 2;
+       msg.iov[0].buf = &hdr;
+       msg.iov[0].len = sizeof(hdr);
+       msg.iov[1].buf = data;
+       msg.iov[1].len = data_len;
 
-       frame.hdr.type = RC_PROTO_HELLO;
-       frame.hdr.datalen = data_len;
-       memcpy(frame.buf, data, data_len);
-       return xbeeapp_send_msg(addr, &frame,
-                               data_len + sizeof(struct rc_proto_echo_req), 1);
+       return xbeeapp_send_msg(addr, &msg, 1);
 }
 
 

diff --git a/xbee_user.c b/xbee_user.c
index 81f2fb6..4717313 100644 (file)
--- a/xbee_user.c
+++ b/xbee_user.c
@@ -38,6 +38,7 @@
 
 #include <rdline.h>
 #include <xbee.h>
+#include <xbee_rxtx.h>
 
 #include "rc_proto.h"
 #include "xbee_user.h"
@@ -54,14 +55,13 @@ int xbee_raw = 0;
 int xbee_hexdump = 0;
 int xbee_debug = 0;
 
-static void hexdump(const char *title, const void *buf, unsigned int len)
+static void __hexdump(const void *buf, unsigned int len)
 {
        unsigned int i, out, ofs;
        const unsigned char *data = buf;
 #define LINE_LEN 80
        char line[LINE_LEN];    /* space needed 8+16*3+3+16 == 75 */
 
-       printf_P(PSTR("%s at [%p], len=%d\r\n"), title, data, len);
        ofs = 0;
        while (ofs < len) {
                /* format 1 line in the buffer, then use printk to print them */
@@ -84,8 +84,26 @@ static void hexdump(const char *title, const void *buf, unsigned int len)
        }
 }
 
+static void hexdump_msg(const char *title, const struct xbee_msg *msg)
+{
+       unsigned i;
+
+       printf_P(PSTR("dump %s\r\n"), title);
+       for (i = 0; i < msg->iovlen; i++) {
+               printf_P(PSTR("iovec %d at %p, len=%d\r\n"), i,
+                       msg->iov[i].buf, msg->iov[i].len);
+               __hexdump(msg->iov[i].buf, msg->iov[i].len);
+       }
+}
+
+static void hexdump(const char *title, const void *buf, unsigned int len)
+{
+       printf_P(PSTR("dump %s at [%p], len=%d\r\n"), title, buf, len);
+       __hexdump(buf, len);
+}
+
 static int parse_xmit_status(struct xbee_ctx *ctx,
-                            struct xbee_xmit_status_hdr *frame, unsigned len)
+       struct xbee_xmit_status_hdr *frame, unsigned len)
 {
        (void)len;
 
@@ -116,7 +134,7 @@ static int parse_xmit_status(struct xbee_ctx *ctx,
 }
 
 static int dump_atcmd(struct xbee_ctx *ctx, struct xbee_atresp_hdr *frame,
-              unsigned len)
+       unsigned len)
 {
        char atcmd_str[3];
        const struct xbee_atcmd *cmd_pgm;
@@ -362,17 +380,12 @@ int8_t xbeeapp_rx(struct xbee_dev *dev, int channel, int type,
        return ret;
 }
 
-static int xbeeapp_send(struct xbee_ctx *ctx, int type, void *buf, unsigned len,
-                       int foreground)
+static int xbeeapp_send(struct xbee_ctx *ctx, int type, struct xbee_msg *msg,
+       int foreground)
 {
        int ret;
        int channel;
 
-       if (len > XBEE_MAX_FRAME_LEN) {
-               printf_P(PSTR("frame too large\r\n"));
-               return -1;
-       }
-
        /* register a channel */
        channel = xbee_register_channel(xbee_dev, XBEE_CHANNEL_ANY,
                                        xbeeapp_rx, NULL);
@@ -387,13 +400,13 @@ static int xbeeapp_send(struct xbee_ctx *ctx, int type, void *buf, unsigned len,
        xbee_set_opaque(xbee_dev, channel, ctx);
 
        if (xbee_debug)
-               printf_P(PSTR("send frame channel=%d type=0x%x len=%d\r\n"),
-                        channel, type, len);
+               printf_P(PSTR("send frame channel=%d type=0x%x\r\n"),
+                       channel, type);
        if (xbee_hexdump)
-               hexdump("xmit frame", buf, len);
+               hexdump_msg("xmit frame", msg);
 
        /* transmit the frame on this channel */
-       ret = xbee_tx(xbee_dev, channel, type, buf, len);
+       ret = xbee_tx_iovec(xbee_dev, channel, type, msg);
        if (ret < 0) {
                printf_P(PSTR("cannot send\r\n"));
                xbee_unregister_channel(xbee_dev, channel);
@@ -415,15 +428,13 @@ static int xbeeapp_send(struct xbee_ctx *ctx, int type, void *buf, unsigned len,
 
 /* send an AT command with parameters filled by caller. Disable
  * command line until we get the answer or until a timeout occurs */
-int xbeeapp_send_atcmd(const char *atcmd_str,
-                      void *param, unsigned param_len, int foreground,
-                      int (*func)(void *frame, unsigned len, void *arg), void *arg)
+int xbeeapp_send_atcmd(char *atcmd_str, void *param,
+       unsigned param_len, int foreground,
+       int (*func)(void *frame, unsigned len, void *arg), void *arg)
 {
        struct xbee_ctx ctx;
-       struct {
-               struct xbee_atcmd_hdr atcmd;
-               char buf[XBEE_MAX_FRAME_LEN];
-       } __attribute__((packed)) frame;
+       /* struct xbee_atcmd_hdr atcmd_hdr; -> no needed same than atcmd_str */
+       struct xbee_msg msg;
 
        memset(&ctx, 0, sizeof(ctx));
        ctx.atcmd_query[0] = atcmd_str[0];
@@ -431,41 +442,46 @@ int xbeeapp_send_atcmd(const char *atcmd_str,
        ctx.func = func;
        ctx.arg = arg;
 
-       memcpy(&frame.atcmd.cmd, atcmd_str, 2);
-       memcpy(&frame.buf, param, param_len);
+       msg.iovlen = 2;
+       msg.iov[0].buf = atcmd_str;
+       msg.iov[0].len = 2;
+       msg.iov[1].buf = param;
+       msg.iov[1].len = param_len;
 
-       if (xbeeapp_send(&ctx, XBEE_TYPE_ATCMD, &frame,
-                        sizeof(struct xbee_atcmd_hdr) +
-                        param_len, foreground) < 0) {
+       if (xbeeapp_send(&ctx, XBEE_TYPE_ATCMD, &msg, foreground) < 0)
                return -1;
-       }
 
        return 0;
 }
 
-int xbeeapp_send_msg(uint64_t addr, void *data,
-                    unsigned data_len, int foreground)
+int xbeeapp_send_msg(uint64_t addr, struct xbee_msg *msg, int foreground)
 {
        struct xbee_ctx ctx;
-       struct {
-               struct xbee_xmit_hdr xmit;
-               char buf[XBEE_MAX_FRAME_LEN];
-       } __attribute__((packed)) frame;
+       struct xbee_xmit_hdr xmit_hdr;
+       struct xbee_msg msg2;
+       unsigned i;
+
+       if (msg->iovlen + 2 > XBEE_MSG_MAXIOV) {
+               printf_P(PSTR("too many iovecs\r\n"));
+               return -1;
+       }
+
+       xmit_hdr.dstaddr = htonll(addr);
+       xmit_hdr.reserved = htons(0xFFFE);
+       xmit_hdr.bcast_radius = 0;
+       xmit_hdr.opts = 0;
+
+       msg2.iovlen = msg->iovlen + 1;
+       msg2.iov[0].buf = &xmit_hdr;
+       msg2.iov[0].len = sizeof(xmit_hdr);
+       for (i = 0; i < msg->iovlen; i++)
+               msg2.iov[i+1] = msg->iov[i];
 
        memset(&ctx, 0, sizeof(ctx));
        ctx.atcmd_query[0] = '\0';
 
-       frame.xmit.dstaddr = htonll(addr);
-       frame.xmit.reserved = htons(0xFFFE);
-       frame.xmit.bcast_radius = 0;
-       frame.xmit.opts = 0;
-       memcpy(&frame.buf, data, data_len);
-
-       if (xbeeapp_send(&ctx, XBEE_TYPE_XMIT, &frame,
-                        sizeof(struct xbee_xmit_hdr) +
-                        data_len, foreground) < 0) {
+       if (xbeeapp_send(&ctx, XBEE_TYPE_XMIT, &msg2, foreground) < 0)
                return -1;
-       }
 
        return 0;
 }

diff --git a/xbee_user.h b/xbee_user.h
index ced5363..daedeee 100644 (file)
--- a/xbee_user.h
+++ b/xbee_user.h
@@ -29,6 +29,7 @@
 #define _XBEE_USER_H_
 
 #include <callout.h>
+#include <xbee_rxtx.h>
 
 /* used for timeouts and xbee rx callback */
 struct xbee_ctx {
@@ -46,14 +47,28 @@ extern int xbee_raw;
 extern int xbee_hexdump;
 extern int xbee_debug;
 
+/* we use a specific structure to send packets. It allows to prepend some
+ * data in the frame without doing a copy. */
+struct xbeeapp_pkt {
+       char *buf;
+       unsigned len;
+       unsigned headroom;
+       unsigned tailroom;
+};
+
+/* callback registered to xbee module, called when a xbee frame is received */
 int8_t xbeeapp_rx(struct xbee_dev *dev, int channel, int type,
-                 void *frame, unsigned len, void *opaque);
-int xbeeapp_send_atcmd(const char *atcmd_str,
-                      void *param, unsigned param_len, int foreground,
-                      int (*func)(void *frame, unsigned len, void *arg),
-                      void *arg);
-int xbeeapp_send_msg(uint64_t addr, void *data,
-                    unsigned data_len, int foreground);
+       void *frame, unsigned len, void *opaque);
+
+/* Send an AT command to the xbee device. The callback function for the answer
+ * is given as a parameter */
+int xbeeapp_send_atcmd(char *atcmd_str, void *param,
+       unsigned param_len, int foreground,
+       int (*func)(void *frame, unsigned len, void *arg),
+       void *arg);
+
+/* send a message to a peer */
+int xbeeapp_send_msg(uint64_t addr, struct xbee_msg *msg, int foreground);
 
 void xbee_stdin_enable(void);
 void xbee_stdin_disable(void);