initial work on reproducer-rewriter

1 files changed, 165 insertions, 0 deletions

diff --git a/tools/reproduceriter.py b/tools/reproduceriter.py
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+'''
+
+* This is a work in progress *
+
+Reproducer Rewriter
+===================
+
+Processes a project and rewrites it so as to generate deterministic,
+reproducible automatic results. For example, you can run this on a
+game, and then when the game is run it will record user input and
+sources of nondeterminism like Math.random(). You can then run
+that recording as a benchmark or as a demo, it should give nearly
+identical results every time it is run to the data that was
+recorded.
+
+Usage:
+
+1. Run this script as
+
+    reproduceriter.py IN_DIR OUT_DIR FIRST_JS START_COMMAND
+
+   IN_DIR should be the project directory, and OUT_DIR will be
+   created with the instrumented code (OUT_DIR should not
+   exist). FIRST_JS should be a path (relative to IN_DIR) to
+   the first JavaScript file loaded by the project (this tool
+   will add code to that). 
+
+2. Run the instrumented project in OUR_DIR and interact with
+   the program. When you are done recording, open the web
+   console and run
+
+    Recorder.finish();
+
+   This will write out the recorded data into the current tab.
+   Save it as
+
+    repro.data
+
+   in OUT_DIR.
+
+3. To re-play the recorded data, run the instrumented build
+   with
+
+    &reproduce=repro.data
+
+Notes:
+
+ * When we start to replay events, the assumption is that
+   there is nothing asynchronous that affects execution. So
+   asynchronous loading of files should have already
+   completed.
+
+   TODO: start running recorded events with some trigger, for example the fullscreen button in BananaBread
+'''
+
+import os, sys, shutil
+
+assert len(sys.argv) == 4, 'Usage: reproduceriter.py IN_DIR OUT_DIR'
+
+# Process input args
+
+in_dir = sys.argv[1]
+out_dir = sys.argv[2]
+first_js = sys.argv[3]
+
+assert not os.path.exists(out_dir), 'OUT_DIR must not exist'
+assert os.path.exists(os.path.join(in_dir, first_js))
+
+# Copy project
+
+shutil.copytree(in_dir, out_dir)
+
+# Add our boilerplate
+
+open(os.path.join(out_dir, first_js), 'w').write('''
+var Recorder = (function() {
+  var recorder;
+  var init = '&reproduce=';
+  var initLocation = window.location.search.indexOf(init);
+  var replaying = initLocation >= 0
+  if (replaying) {
+    // load recording
+    var dataPath = window.location.search.substring(initLocation);
+    var baseURL = window.location.toString().replace('://', 'cheez999').split('?')[0].split('/')[0].replace('cheez999', '://');
+    if (baseURL[baseURL.length-1] != '/') baseURL += '/';
+    var request = new XMLHttpRequest();
+    request.open('GET', baseURL + dataPath, false);
+    request.send();
+    recorder = JSON.parse(request.responseText);
+    // prepare to replay
+    // Math.random
+    var warned = false;
+    Math.random = function() {
+      if (recorder.randoms.length > 0) {
+        return recorder.randoms.shift();
+      } else {
+        if (!warned) {
+          console.log('warning: consuming too many values!')
+          warned = true;
+        }
+        return Math.random();
+      }
+    };
+    // Date.now, performance.now
+    var warned = false;
+    Date.now = function() {
+      if (recorder.dnows.length > 0) {
+        return recorder.dnows.shift();
+      } else {
+        if (!warned) {
+          console.log('warning: consuming too many values!')
+          warned = true;
+        }
+        return Date.now();
+      }
+    };
+    var warned = false;
+    performance.now = function() {
+      if (recorder.pnows.length > 0) {
+        return recorder.pnows.shift();
+      } else {
+        if (!warned) {
+          console.log('warning: consuming too many values!')
+          warned = true;
+        }
+        return performance.now();
+      }
+    };
+  } else {
+    // prepare to record
+    recorder = {};
+    // Math.random
+    recorder.randoms = [];
+    var random = Math.random()
+    Math.random = function() {
+      var ret = random();
+      recorder.randoms.push(ret);
+      return ret;
+    };
+    // Date.now, performance.now
+    recorder.dnows = [];
+    var dnow = Date.now();
+    Date.now = function() {
+      var ret = dnow();
+      recorder.dnows.push(ret);
+      return ret;
+    };
+    recorder.pnows = [];
+    var pnow = performance.now();
+    performance.now = function() {
+      var ret = pnow();
+      recorder.pnows.push(ret);
+      return ret;
+    };
+    // finish
+    recorder.finish = function() {
+      document.write(JSON.stringify(recorder));
+      throw 'all done, remember to save!';
+    };
+  }
+  return recorder;
+})();
+''' + open(os.path.join(in_dir, first_js)).read()
+)
+