chore(cbindings): Adding cpp example that integrates the 'libwaku' (#…

…2079) * Adding cpp example that integrates the `libwaku` --------- Co-authored-by: NagyZoltanPeter <113987313+NagyZoltanPeter@users.noreply.github.com>
waku-org · Sep 28, 2023 · 8455b8d · 8455b8d
1 parent c5aa970
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diff --git a/Makefile b/Makefile
@@ -273,6 +273,18 @@ cwaku_example: | build libwaku
 		vendor/nim-libbacktrace/libbacktrace_wrapper.o \
 		vendor/nim-libbacktrace/install/usr/lib/libbacktrace.a
 
+cppwaku_example: | build libwaku
+	echo -e $(BUILD_MSG) "build/$@" && \
+		g++ -o "build/$@" \
+		./examples/cpp/waku.cpp \
+		./examples/cpp/base64.cpp \
+		-lwaku -Lbuild/ \
+		-pthread -ldl -lm \
+		-lminiupnpc -Lvendor/nim-nat-traversal/vendor/miniupnp/miniupnpc/build/ \
+		-lnatpmp -Lvendor/nim-nat-traversal/vendor/libnatpmp-upstream/ \
+		vendor/nim-libbacktrace/libbacktrace_wrapper.o \
+		vendor/nim-libbacktrace/install/usr/lib/libbacktrace.a
+
 nodejswaku: | build deps
 		echo -e $(BUILD_MSG) "build/$@" && \
 		node-gyp build --directory=examples/nodejs/

diff --git a/examples/cpp/base64.cpp b/examples/cpp/base64.cpp
@@ -0,0 +1,53 @@
+
+#include <vector>
+#include "base64.h"
+
+// Base64 encoding
+// source: https://nachtimwald.com/2017/11/18/base64-encode-and-decode-in-c/
+size_t b64_encoded_size(size_t inlen)
+{
+	size_t ret;
+
+	ret = inlen;
+	if (inlen % 3 != 0)
+		ret += 3 - (inlen % 3);
+	ret /= 3;
+	ret *= 4;
+
+	return ret;
+}
+
+const char b64chars[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+void b64_encode(char* in, size_t len, std::vector<char>& out)
+{
+	size_t  elen;
+	size_t  i;
+	size_t  j;
+	size_t  v;
+
+	if (in == NULL || len == 0)
+		return;
+
+	elen = b64_encoded_size(len);
+	out.reserve(elen+1);
+
+	for (i=0, j=0; i<len; i+=3, j+=4) {
+		v = in[i];
+		v = i+1 < len ? v << 8 | in[i+1] : v << 8;
+		v = i+2 < len ? v << 8 | in[i+2] : v << 8;
+
+		out[j]   = b64chars[(v >> 18) & 0x3F];
+		out[j+1] = b64chars[(v >> 12) & 0x3F];
+		if (i+1 < len) {
+			out[j+2] = b64chars[(v >> 6) & 0x3F];
+		} else {
+			out[j+2] = '=';
+		}
+		if (i+2 < len) {
+			out[j+3] = b64chars[v & 0x3F];
+		} else {
+			out[j+3] = '=';
+		}
+	}
+}
diff --git a/examples/cpp/base64.h b/examples/cpp/base64.h
@@ -0,0 +1,11 @@
+
+#ifndef _BASE64_H_
+#define _BASE64_H_
+
+#include <stdlib.h>
+
+size_t b64_encoded_size(size_t inlen);
+
+void b64_encode(char* in, size_t len, std::vector<char>& out);
+
+#endif
diff --git a/examples/cpp/waku.cpp b/examples/cpp/waku.cpp
@@ -0,0 +1,271 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <argp.h>
+#include <signal.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <vector>
+#include <iostream>
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+#include "base64.h"
+#include "../../library/libwaku.h"
+
+#define WAKU_CALL(call)                                                        \
+do {                                                                           \
+  int ret = call;                                                              \
+  if (ret != 0) {                                                              \
+    std::cout << "Failed the call to: " << #call << ". Code: " << ret << "\n"; \
+  }                                                                            \
+} while (0)
+
+struct ConfigNode {
+    char    host[128];
+    int          port;
+    char     key[128];
+    int         relay;
+    char  peers[2048];
+};
+
+// Arguments parsing
+static char doc[] = "\nC example that shows how to use the waku library.";
+static char args_doc[] = "";
+
+static struct argp_option options[] = {
+    { "host",  'h', "HOST",  0, "IP to listen for for LibP2P traffic. (default: \"0.0.0.0\")"},
+    { "port",  'p', "PORT",  0, "TCP listening port. (default: \"60000\")"},
+    { "key",   'k', "KEY",   0, "P2P node private key as 64 char hex string."},
+    { "relay", 'r', "RELAY", 0, "Enable relay protocol: 1 or 0. (default: 1)"},
+    { "peers", 'a', "PEERS", 0, "Comma-separated list of peer-multiaddress to connect\
+ to. (default: \"\") e.g. \"/ip4/127.0.0.1/tcp/60001/p2p/16Uiu2HAmVFXtAfSj4EiR7mL2KvL4EE2wztuQgUSBoj2Jx2KeXFLN\""},
+    { 0 }
+};
+
+static error_t parse_opt(int key, char *arg, struct argp_state *state) {
+
+    struct ConfigNode *cfgNode = (ConfigNode *) state->input;
+    switch (key) {
+        case 'h':
+            snprintf(cfgNode->host, 128, "%s", arg);
+            break;
+        case 'p':
+            cfgNode->port = atoi(arg);
+            break;
+        case 'k':
+            snprintf(cfgNode->key, 128, "%s", arg);
+            break;
+        case 'r':
+            cfgNode->relay = atoi(arg);
+            break;
+        case 'a':
+            snprintf(cfgNode->peers, 2048, "%s", arg);
+            break;
+        case ARGP_KEY_ARG:
+            if (state->arg_num >= 1) /* Too many arguments. */
+            argp_usage(state);
+            break;
+        case ARGP_KEY_END:
+            break;
+        default:
+            return ARGP_ERR_UNKNOWN;
+        }
+
+    return 0;
+}
+
+static struct argp argp = { options, parse_opt, args_doc, doc, 0, 0, 0 };
+
+// Beginning of UI program logic
+
+enum PROGRAM_STATE {
+    MAIN_MENU,
+    SUBSCRIBE_TOPIC_MENU,
+    CONNECT_TO_OTHER_NODE_MENU,
+    PUBLISH_MESSAGE_MENU
+};
+
+enum PROGRAM_STATE current_state = MAIN_MENU;
+
+void show_main_menu() {
+    printf("\nPlease, select an option:\n");
+    printf("\t1.) Subscribe to topic\n");
+    printf("\t2.) Connect to other node\n");
+    printf("\t3.) Publish a message\n");
+}
+
+void handle_user_input() {
+    char cmd[1024];
+    memset(cmd, 0, 1024);
+    int numRead = read(0, cmd, 1024);
+    if (numRead <= 0) {
+        return;
+    }
+
+    int c;
+    while ( (c = getchar()) != '\n' && c != EOF ) { }
+
+    switch (atoi(cmd))
+    {
+    case SUBSCRIBE_TOPIC_MENU:
+    {
+        printf("Indicate the Pubsubtopic to subscribe:\n");
+        char pubsubTopic[128];
+        scanf("%127s", pubsubTopic);
+        // if (!waku_relay_subscribe(pubsubTopic, &mResp)) {
+        //     printf("Error subscribing to PubsubTopic: %s\n", mResp->data);
+        // }
+        // printf("Waku Relay subscription response: %s\n", mResp->data);
+
+        show_main_menu();
+    }
+    break;
+
+    case CONNECT_TO_OTHER_NODE_MENU:
+        printf("Connecting to a node. Please indicate the peer Multiaddress:\n");
+        printf("e.g.: /ip4/127.0.0.1/tcp/60001/p2p/16Uiu2HAmVFXtAfSj4EiR7mL2KvL4EE2wztuQgUSBoj2Jx2KeXFLN\n");
+        char peerAddr[512];
+        scanf("%511s", peerAddr);
+        // if (!waku_connect(peerAddr, 10000 /* timeoutMs */, &mResp)) {
+        //     printf("Couldn't connect to the remote peer: %s\n", mResp->data);
+        // }
+        show_main_menu();
+    break;
+
+    case PUBLISH_MESSAGE_MENU:
+    {
+        printf("Indicate the Pubsubtopic:\n");
+        char pubsubTopic[128];
+        scanf("%127s", pubsubTopic);
+
+        printf("Type the message tp publish:\n");
+        char msg[1024];
+        scanf("%1023s", msg);
+
+        char jsonWakuMsg[1024];
+        std::vector<char> msgPayload;
+        b64_encode(msg, strlen(msg), msgPayload);
+
+        // waku_content_topic("appName",
+        //                     1,
+        //                     "contentTopicName",
+        //                     "encoding",
+        //                     &mResp);
+
+        // snprintf(jsonWakuMsg,
+        //          1024,
+        //          "{\"payload\":\"%s\",\"content_topic\":\"%s\"}",
+        //          msgPayload, mResp->data);
+
+        // free(msgPayload);
+
+        // waku_relay_publish(pubsubTopic, jsonWakuMsg, 10000 /*timeout ms*/, &mResp);
+        // printf("waku relay response [%s]\n", mResp->data);
+        show_main_menu();
+    }
+    break;
+
+    case MAIN_MENU:
+        break;
+    }
+}
+
+// End of UI program logic
+
+void show_help_and_exit() {
+    printf("Wrong parameters\n");
+    exit(1);
+}
+
+void event_handler(const char* msg, size_t len) {
+    printf("Receiving message %s\n", msg);
+}
+
+void handle_error(const char* msg, size_t len) {
+    printf("Error: %s\n", msg);
+    exit(1);
+}
+
+template <class F>
+auto cify(F&& f) {
+  static F fn = std::forward<F>(f);
+  return [](const char* msg, size_t len) {
+    return fn(msg, len);
+  };
+}
+
+int main(int argc, char** argv) {
+
+    struct ConfigNode cfgNode;
+    // default values
+    snprintf(cfgNode.host, 128, "0.0.0.0");
+    snprintf(cfgNode.key, 128,
+             "364d111d729a6eb6d2e6113e163f017b5ef03a6f94c9b5b7bb1bb36fa5cb07a9");
+    cfgNode.port = 60000;
+    cfgNode.relay = 1;
+
+    if (argp_parse(&argp, argc, argv, 0, 0, &cfgNode)
+                    == ARGP_ERR_UNKNOWN) {
+        show_help_and_exit();
+    }
+
+    char jsonConfig[1024];
+    snprintf(jsonConfig, 1024, "{ \
+                                    \"host\": \"%s\",   \
+                                    \"port\": %d,       \
+                                    \"key\": \"%s\",    \
+                                    \"relay\": %s,      \
+                                }", cfgNode.host,
+                                    cfgNode.port,
+                                    cfgNode.key,
+                                    cfgNode.relay ? "true":"false");
+
+    WAKU_CALL(waku_new(jsonConfig, cify([](const char* msg, size_t len) {
+        std::cout << "Error: " << msg << std::endl;
+        exit(1);
+    })));
+
+    // example on how to retrieve a value from the `libwaku` callback.
+    std::string defaultPubsubTopic;
+    WAKU_CALL(waku_default_pubsub_topic(cify([&defaultPubsubTopic](const char* msg, size_t len) {
+        defaultPubsubTopic = msg;
+    })));
+
+    std::cout << "Default pubsub topic: " << defaultPubsubTopic << std::endl;
+
+    WAKU_CALL(waku_version(cify([&](const char* msg, size_t len) {
+        std::cout << "Git Version: " << msg << std::endl;
+    })));
+
+    printf("Bind addr: %s:%u\n", cfgNode.host, cfgNode.port);
+    printf("Waku Relay enabled: %s\n", cfgNode.relay == 1 ? "YES": "NO");
+
+    std::string pubsubTopic;
+    WAKU_CALL(waku_pubsub_topic("example", cify([&](const char* msg, size_t len) {
+        pubsubTopic = msg;
+    })));
+
+    std::cout << "Custom pubsub topic: " << pubsubTopic << std::endl;
+
+    waku_set_event_callback(event_handler);
+    waku_start();
+
+    WAKU_CALL( waku_connect(cfgNode.peers,
+                        10000 /* timeoutMs */,
+                        handle_error) );
+
+    WAKU_CALL( waku_relay_subscribe(defaultPubsubTopic.c_str(),
+                                    handle_error) );
+
+    std::cout << "Establishing connection with: " << cfgNode.peers << std::endl;
+    WAKU_CALL(waku_connect(cfgNode.peers, 10000 /* timeoutMs */, handle_error));
+
+    show_main_menu();
+    while(1) {
+        handle_user_input();
+    }
+}
diff --git a/library/libwaku.h b/library/libwaku.h
@@ -11,6 +11,10 @@
 #define RET_ERR               1
 #define RET_MISSING_CALLBACK  2
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef void (*WakuCallBack) (const char* msg, size_t len_0);
 
 // Creates a new instance of the waku node.
@@ -51,4 +55,8 @@ int waku_connect(const char* peerMultiAddr,
                  unsigned int timeoutMs,
                  WakuCallBack onErrCb);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* __libwaku__ */