initial implementation

Author: juliangruber

.gitignore

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+node_modules
+*.sw*

Makefile

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+
+test:
+	@node_modules/.bin/mocha --reporter spec
+
+.PHONY: test
+

index.js

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+
+module.exports = extract;
+
+var comma = ','.charCodeAt(0);
+
+function extract(buf, key){
+  for (var i = 0; i < buf.length; i++) {
+    var match = true;
+    for (var j = 0; j < key.length; j++) {
+      if (buf[i + j] != key.charCodeAt(j)) {
+        match = false;
+        break;
+      }
+    }
+    if (!match) continue;
+
+    var start = i + key.length + 2;
+    var end;
+    for (var j = start; j < buf.length; j++) {
+      if (buf[j] == comma) {
+        end = j;
+        break;
+      }
+    }
+
+    var json = buf.toString('utf8', start, end);
+    return JSON.parse(json);
+  }
+}
+

package.json

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+{
+  "name": "binary-extract",
+  "description": "Extract a value from a binary json blob",
+  "version": "0.0.0",
+  "repository": "segmentio/binary-extract",
+  "license": "MIT",
+  "devDependencies": {
+    "mocha": "~1.18.0"
+  }
+}

test.js

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+
+var assert = require('assert');
+var equal = assert.equal;
+var extract = require('./');
+
+var obj = {
+  foo: 'bar',
+  bar: 3,
+  baz: {
+    beep: 'boop'
+  }
+}
+var buf = Buffer(JSON.stringify(obj));
+
+describe('extract(buf, key)', function(){
+  it('should extract a value', function(){
+    equal(extract(buf, 'foo'), 'bar');
+  })
+})
+