some improvements

backend-c/Makefile

@@ -1,4 +1,4 @@
-TARGET = hello_world
+TARGET = fluid
 CC = /opt/wasi-sdk/bin/clang
 SYSROOT = /opt/wasi-sdk/share/wasi-sysroot
 TARGET_TRIPLE = wasm32-unknown-wasi

backend-c/run.sh

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+
+set -e
+set -o pipefail
+
+mkdir -p wasm
+
+# Download SQLite
+SQLITE="sqlite3_0.2.0.wasm"
+if [ ! -f "wasm/$SQLITE" ]; then
+  echo "Downloading $SQLITE..."
+  wget -q https://github.com/fluencelabs/sqlite/releases/download/v0.2.0_w/$SQLITE -O ./wasm/$SQLITE
+fi
+
+# Build fluid WASM module
+echo "Building to WASM..."
+docker-compose up --build
+cp fluid.wasm wasm/
+echo
+
+# Run it all on 30000 port with default Fluence API
+echo "Running..."
+docker rm -f frun &>/dev/null || true
+echo 'docker run -d --name frun --rm -v "$(pwd)/wasm:/code" -p 30000:30000 fluencelabs/frun:latest'
+docker run -d --name frun --rm -v "$(pwd)/wasm:/code" -p 30000:30000 fluencelabs/frun:latest >/dev/null
+echo
+
+# Wait for app to be initialized
+sleep 1 && (docker logs -f frun 2>&1 &) | grep -q initialized && sleep 1
+
+
+
+############################################
+### *** --- === Sending post === --- *** ###
+############################################
+
+# Assign json to a variable using heredoc technique
+JSON=$(cat <<JSON
+{"action":"Post","message":"I'm nice, you're nice, it's nice!","username":"random_joe"}
+JSON
+)
+
+echo -e "Sending post: $JSON"
+# Send json as a request, and receive result
+RESPONSE=$(curl -s 'http://localhost:30000/apps/0/tx' --data $'sessionId/0\n'"$JSON" --compressed)
+RESPONSE=$(echo "$RESPONSE" | jq -r .result.data | base64 --decode 2>/dev/null || echo "$RESPONSE")
+# Parse json or print response as is
+echo "$RESPONSE" | jq . 2>/dev/null || echo "$RESPONSE"
+
+
+##############################################
+### *** --- === Fetching posts === --- *** ###
+##############################################
+
+# Assign json to a variable using heredoc technique
+JSON=$(cat <<JSON
+{"action":"Fetch", "handle": "random_joe", "offset": 0, "count": 10}
+JSON
+)
+
+echo -e "Fetching posts: $JSON"
+
+# Send json as a request, and receive result
+RESPONSE=$(curl -s 'http://localhost:30000/apps/0/tx' --data $'sessionId/1\n'"$JSON" --compressed)
+RESPONSE=$(echo "$RESPONSE" | jq -r .result.data | base64 --decode 2>/dev/null || echo "$RESPONSE")
+
+# Parse json or print response as is
+echo "$RESPONSE" | jq . 2>/dev/null || echo "$RESPONSE"
+
+
+# Remove frun container
+echo -e "Stopping..."
+docker rm -f frun >/dev/null

backend-c/sdk/syscalls_stubs.c

@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+size_t __stdio_write(FILE *f, const unsigned char *buf, size_t len) {
+    return 1;
+}
+
+int __stdio_close(FILE *f) {
+    return 1;
+}
+
+off_t __stdio_seek(FILE *_f, off_t _offset, int _value) {
+    return 1;
+}
+

backend-c/src/main.c

@@ -1,23 +1,11 @@
+#include "model.h"
 #include "../sdk/allocator.h"
 #include "../sdk/logger.h"
-#include "model.h"
+#include "../sdk/syscalls_stubs.c"
 #include "../libs/tiny-json/tiny-json.h"
 
 #include <string.h>
 #include <stdlib.h>
-#include <stdio.h>
-
-size_t __stdio_write(FILE *f, const unsigned char *buf, size_t len) {
-    return 1;
-}
-
-int __stdio_close(FILE *f) {
-    return 1;
-}
-
-off_t __stdio_seek(FILE *_f, off_t _offset, int _value) {
-    return 0;
-}
 
 char *prepare_response(const char *response, int response_length) {
     const int RESPONSE_SIZE_BYTES = 4;
@@ -38,17 +26,16 @@ const char *fetch_posts_request(const json_t *json);
 bool isInited = 0;
 
 const char *invoke(char *str, int length) {
+    // initialize SQLite by creating schema
     if(0 == isInited) {
         create_scheme();
         isInited = 1;
     }
 
-    wasm_log(str, length);
-    wasm_log("\n", 1);
-
     json_t pool[10];
     const unsigned int pool_size = sizeof pool / sizeof *pool;
 
+    // try to parse json and extract action field
     const json_t *json = json_create(str, pool, pool_size);
     if(!json) {
         const char error[] = "Mailformed json given";
@@ -68,12 +55,14 @@ const char *invoke(char *str, int length) {
 
     const char *action = json_getValue(action_json);
 
+    // use action to determine the desired activity
     const char *result = "";
     if(0 == strcmp(action, "Post")) {
         result = add_post_request(json);
     } else if(0 == strcmp(action, "Fetch")) {
         result = fetch_posts_request(json);
     } else {
+        // no suitable action given
         char *error = (char *)malloc(1024);
         const int error_size = snprintf(error, 1024, "%s given as the action field, but only `Post` and `Fetch` are supported", action);
         result = prepare_response(error, error_size);
@@ -83,6 +72,7 @@ const char *invoke(char *str, int length) {
 }
 
 const char *add_post_request(const json_t *json) {
+    // try to extract username and message properties
     const json_t *username_json = json_getProperty(json, "username");
     const json_t *message_json = json_getProperty(json, "message");
     if(0 == message_json || 0 == username_json) {
@@ -105,6 +95,7 @@ const char *add_post_request(const json_t *json) {
         return prepare_response(error, sizeof error);
     }
 
+    // returns the updated post count to the client
     const char *count = get_posts_count();
     if(0 == count) {
         const char error[] = "get_posts_count failed";
@@ -118,6 +109,7 @@ const char *add_post_request(const json_t *json) {
 }
 
 const char *fetch_posts_request(const json_t *json) {
+    // try to extract username, offset and count fields
     const json_t *username_json = json_getProperty(json, "username");
     const json_t *offset_json = json_getProperty(json, "offset");
     const json_t *count_json = json_getProperty(json, "count");
@@ -142,6 +134,7 @@ const char *fetch_posts_request(const json_t *json) {
 
     char *result = "";
     if(0 == username_json) {
+        // if no username specified, jsut return all posts
         result = get_all_posts(offset, count);
         if(0 == result) {
             const char error[] = "get_all_posts failed";

backend-c/src/model.c

@@ -18,7 +18,7 @@ char *add_post(const char *username, int username_length, const char *message, i
     const int request_size = username_length + message_length + 50;
     char *add_sql = (char *)malloc(request_size);
 
-    const int add_sql_length = snprintf(add_sql, request_size, "INSERT INTO messages VALUES(%s, %s)", message, username);
+    const int add_sql_length = snprintf(add_sql, request_size, "INSERT INTO messages VALUES(\"%s\", \"%s\")", message, username);
     if(add_sql_length < 0) {
         return 0;
     }