HP smart contract nodejs library. (#101)

examples/nodejs_contract/.gitignore

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+node_modules

examples/nodejs_contract/echo_contract.js

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+const { HotPocketContract } = require("./hp-contract-lib");
+const fs = require('fs');
+
+const hpc = new HotPocketContract();
+
+//console.log("===Echo contract started===");
+
+// We just save execution timestamp as an example state file change.
+if (!hpc.readonly)
+    fs.appendFileSync("exects.txt", "ts:" + hpc.timestamp + "\n");
+
+Object.keys(hpc.users).forEach(function (key) {
+
+    const user = hpc.users[key];
+    const inputBuf = user.readInput();
+    if (inputBuf) {
+        const userInput = inputBuf.toString("utf8");
+
+        // Append user input to a state file if not in read only mode.
+        if (!hpc.readonly)
+            fs.appendFileSync("userinputs.txt", userInput + "\n");
+
+        if (userInput == "ts")
+            user.sendOutput(fs.readFileSync("exects.txt"));
+        else
+            user.sendOutput("Echoing: " + userInput);
+    }
+});
+
+//console.log("===Echo contract ended===");

examples/nodejs_contract/file_contract.js

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+const fs = require('fs');
+const bson = require('bson');
+
+//console.log("===File contract started===");
+
+const hpargs = JSON.parse(fs.readFileSync(0, 'utf8'));
+//console.log("Contract args received from hp: " + hpargs);
+
+Object.keys(hpargs.usrfd).forEach(function (key) {
+    const userfds = hpargs.usrfd[key];
+
+    if (userfds[0] != -1) {
+
+        const input = fs.readFileSync(userfds[0]);
+        const msg = bson.deserialize(input);
+
+        if (msg.type == "upload") {
+            if (fs.existsSync(msg.fileName)) {
+                fs.writeSync(userfds[1], bson.serialize({
+                    type: "uploadResult",
+                    status: "already_exists",
+                    fileName: msg.fileName
+                }));
+            }
+            else if (msg.content.length > 10 * 1024 * 1024) { // 10MB
+                fs.writeSync(userfds[1], bson.serialize({
+                    type: "uploadResult",
+                    status: "too_large",
+                    fileName: msg.fileName
+                }));
+            }
+            else {
+
+                // Save the file.
+                fs.writeFileSync(msg.fileName, msg.content.buffer);
+                
+                fs.writeSync(userfds[1], bson.serialize({
+                    type: "uploadResult",
+                    status: "ok",
+                    fileName: msg.fileName
+                }));
+            }
+        }
+        else if (msg.type == "delete") {
+            if (fs.existsSync(msg.fileName)) {
+                fs.unlinkSync(msg.fileName);
+                fs.writeSync(userfds[1], bson.serialize({
+                    type: "deleteResult",
+                    status: "ok",
+                    fileName: msg.fileName
+                }));
+            }
+            else {
+                fs.writeSync(userfds[1], bson.serialize({
+                    type: "deleteResult",
+                    status: "not_found",
+                    fileName: msg.fileName
+                }));
+            }
+        }
+        else if (msg.type == "download") {
+            if (fs.existsSync(msg.fileName)) {
+                const fileContent = fs.readFileSync(msg.fileName);
+                fs.writeSync(userfds[1], bson.serialize({
+                    type: "downloadResult",
+                    status: "ok",
+                    fileName: msg.fileName,
+                    content: fileContent
+                }));
+            }
+            else {
+                fs.writeSync(userfds[1], bson.serialize({
+                    type: "downloadResult",
+                    status: "not_found",
+                    fileName: msg.fileName
+                }));
+            }
+        }
+    }
+});
+
+//console.log("===File contract ended===");

examples/nodejs_contract/hp-contract-lib.js

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+const fs = require('fs');
+
+function HotPocketContract() {
+    const hpargs = JSON.parse(fs.readFileSync(0, 'utf8'));
+    this.readonly = hpargs.readonly;
+    this.timestamp = hpargs.ts;
+    this.users = {};
+
+    Object.keys(hpargs.usrfd).forEach((userPubKey) => {
+        const userfds = hpargs.usrfd[userPubKey];
+        this.users[userPubKey] = new HotPocketChannel(userfds[0], userfds[1]);
+    });
+}
+
+function HotPocketChannel(infd, outfd) {
+    this.readInput = function () {
+        return infd == -1 ? null : fs.readFileSync(infd);
+    }
+
+    this.sendOutput = function (output) {
+        fs.writeFileSync(outfd, output);
+    }
+}
+
+module.exports = {
+    HotPocketContract
+}

examples/nodejs_contract/package-lock.json

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+{
+    "requires": true,
+    "lockfileVersion": 1,
+    "dependencies": {
+        "base64-js": {
+            "version": "1.3.1",
+            "resolved": "https://registry.npmjs.org/base64-js/-/base64-js-1.3.1.tgz",
+            "integrity": "sha512-mLQ4i2QO1ytvGWFWmcngKO//JXAQueZvwEKtjgQFM4jIK0kU+ytMfplL8j+n5mspOfjHwoAg+9yhb7BwAHm36g=="
+        },
+        "bson": {
+            "version": "4.0.4",
+            "resolved": "https://registry.npmjs.org/bson/-/bson-4.0.4.tgz",
+            "integrity": "sha512-Ioi3TD0/1V3aI8+hPfC56TetYmzfq2H07jJa9A1lKTxWsFtHtYdLMGMXjtGEg9v0f72NSM07diRQEUNYhLupIA==",
+            "requires": {
+                "buffer": "^5.1.0",
+                "long": "^4.0.0"
+            }
+        },
+        "buffer": {
+            "version": "5.6.0",
+            "resolved": "https://registry.npmjs.org/buffer/-/buffer-5.6.0.tgz",
+            "integrity": "sha512-/gDYp/UtU0eA1ys8bOs9J6a+E/KWIY+DZ+Q2WESNUA0jFRsJOc0SNUO6xJ5SGA1xueg3NL65W6s+NY5l9cunuw==",
+            "requires": {
+                "base64-js": "^1.0.2",
+                "ieee754": "^1.1.4"
+            }
+        },
+        "ieee754": {
+            "version": "1.1.13",
+            "resolved": "https://registry.npmjs.org/ieee754/-/ieee754-1.1.13.tgz",
+            "integrity": "sha512-4vf7I2LYV/HaWerSo3XmlMkp5eZ83i+/CDluXi/IGTs/O1sejBNhTtnxzmRZfvOUqj7lZjqHkeTvpgSFDlWZTg=="
+        },
+        "long": {
+            "version": "4.0.0",
+            "resolved": "https://registry.npmjs.org/long/-/long-4.0.0.tgz",
+            "integrity": "sha512-XsP+KhQif4bjX1kbuSiySJFNAehNxgLb6hPRGJ9QsUr8ajHkuXGdrHmFUTUUXhDwVX2R5bY4JNZEwbUiMhV+MA=="
+        }
+    }
+}

examples/nodejs_contract/package.json

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+{
+    "dependencies": {
+        "bson": "4.0.4"
+    }
+}