4 files changed, 249 insertions, 0 deletions
diff --git a/devtools/shared/platform/CacheEntry.sys.mjs b/devtools/shared/platform/CacheEntry.sys.mjs
new file mode 100644
index 0000000000..761f0d2946
--- /dev/null
+++ b/devtools/shared/platform/CacheEntry.sys.mjs
@@ -0,0 +1,115 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  NetworkHelper:
+    "resource://devtools/shared/network-observer/NetworkHelper.sys.mjs",
+});
+
+/**
+ * Global cache session object.
+ */
+let gCacheSession = null;
+
+/**
+ * Get (and create if necessary) a cache session / cache storage session.
+ *
+ * @param {nsIRequest} request
+ */
+function getCacheSession(request) {
+  if (!gCacheSession) {
+    try {
+      const cacheService = Services.cache2;
+      if (cacheService) {
+        let loadContext = lazy.NetworkHelper.getRequestLoadContext(request);
+        if (!loadContext) {
+          // Get default load context if we can't fetch.
+          loadContext = Services.loadContextInfo.default;
+        }
+        gCacheSession = cacheService.diskCacheStorage(loadContext);
+      }
+    } catch (e) {
+      gCacheSession = null;
+    }
+  }
+
+  return gCacheSession;
+}
+
+/**
+ * Parses a cache entry returned from the backend to build a response cache
+ * object.
+ *
+ * @param {nsICacheEntry} cacheEntry
+ *     The cache entry from the backend.
+ *
+ * @returns {Object}
+ *     A responseCache object expected by RDP.
+ */
+function buildResponseCacheObject(cacheEntry) {
+  const cacheObject = {};
+  try {
+    if (cacheEntry.storageDataSize) {
+      cacheObject.storageDataSize = cacheEntry.storageDataSize;
+    }
+  } catch (e) {
+    // We just need to handle this in case it's a js file of 0B.
+  }
+  if (cacheEntry.expirationTime) {
+    cacheObject.expirationTime = cacheEntry.expirationTime;
+  }
+  if (cacheEntry.fetchCount) {
+    cacheObject.fetchCount = cacheEntry.fetchCount;
+  }
+  if (cacheEntry.lastFetched) {
+    cacheObject.lastFetched = cacheEntry.lastFetched;
+  }
+  if (cacheEntry.lastModified) {
+    cacheObject.lastModified = cacheEntry.lastModified;
+  }
+  if (cacheEntry.deviceID) {
+    cacheObject.deviceID = cacheEntry.deviceID;
+  }
+  return cacheObject;
+}
+
+/**
+ * Does the fetch for the cache entry from the session.
+ *
+ * @param {nsIRequest} request
+ *     The request object.
+ *
+ * @returns {Promise}
+ *     Promise which resolve a response cache object object, or null if none
+ *     was available.
+ */
+export function getResponseCacheObject(request) {
+  const cacheSession = getCacheSession(request);
+  if (!cacheSession) {
+    return null;
+  }
+
+  return new Promise(resolve => {
+    cacheSession.asyncOpenURI(
+      request.URI,
+      "",
+      Ci.nsICacheStorage.OPEN_SECRETLY,
+      {
+        onCacheEntryCheck: entry => {
+          return Ci.nsICacheEntryOpenCallback.ENTRY_WANTED;
+        },
+        onCacheEntryAvailable: (cacheEntry, isnew, status) => {
+          if (cacheEntry) {
+            const cacheObject = buildResponseCacheObject(cacheEntry);
+            resolve(cacheObject);
+          } else {
+            resolve(null);
+          }
+        },
+      }
+    );
+  });
+}
diff --git a/devtools/shared/platform/clipboard.js b/devtools/shared/platform/clipboard.js
new file mode 100644
index 0000000000..46ea6c5fe6
--- /dev/null
+++ b/devtools/shared/platform/clipboard.js
@@ -0,0 +1,59 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Helpers for clipboard handling.
+
+"use strict";
+
+const clipboardHelper = Cc["@mozilla.org/widget/clipboardhelper;1"].getService(
+  Ci.nsIClipboardHelper
+);
+
+function copyString(string) {
+  clipboardHelper.copyString(string);
+}
+
+/**
+ * Retrieve the current clipboard data matching the flavor "text/plain".
+ *
+ * @return {String} Clipboard text content, null if no text clipboard data is available.
+ */
+function getText() {
+  const flavor = "text/plain";
+
+  const xferable = Cc["@mozilla.org/widget/transferable;1"].createInstance(
+    Ci.nsITransferable
+  );
+
+  if (!xferable) {
+    throw new Error(
+      "Couldn't get the clipboard data due to an internal error " +
+        "(couldn't create a Transferable object)."
+    );
+  }
+
+  xferable.init(null);
+  xferable.addDataFlavor(flavor);
+
+  // Get the data into our transferable.
+  Services.clipboard.getData(xferable, Services.clipboard.kGlobalClipboard);
+
+  const data = {};
+  try {
+    xferable.getTransferData(flavor, data);
+  } catch (e) {
+    // Clipboard doesn't contain data in flavor, return null.
+    return null;
+  }
+
+  // There's no data available, return.
+  if (!data.value) {
+    return null;
+  }
+
+  return data.value.QueryInterface(Ci.nsISupportsString).data;
+}
+
+exports.copyString = copyString;
+exports.getText = getText;
diff --git a/devtools/shared/platform/moz.build b/devtools/shared/platform/moz.build
new file mode 100644
index 0000000000..edbf580c1c
--- /dev/null
+++ b/devtools/shared/platform/moz.build
@@ -0,0 +1,11 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+DevToolsModules(
+    "CacheEntry.sys.mjs",
+    "clipboard.js",
+    "stack.js",
+)
diff --git a/devtools/shared/platform/stack.js b/devtools/shared/platform/stack.js
new file mode 100644
index 0000000000..65ff644091
--- /dev/null
+++ b/devtools/shared/platform/stack.js
@@ -0,0 +1,64 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// A few wrappers for stack-manipulation.  This version of the module
+// is used in chrome code.
+
+"use strict";
+
+/**
+ * Return the Nth path from the stack excluding substr.
+ *
+ * @param {Number}
+ *        n the Nth path from the stack to describe.
+ * @param {String} substr
+ *        A segment of the path that should be excluded.
+ */
+function getNthPathExcluding(n, substr) {
+  let stack = Components.stack.formattedStack.split("\n");
+
+  // Remove this method from the stack
+  stack = stack.splice(1);
+
+  stack = stack.map(line => {
+    if (line.includes(" -> ")) {
+      return line.split(" -> ")[1];
+    }
+    return line;
+  });
+
+  if (substr) {
+    stack = stack.filter(line => {
+      return line && !line.includes(substr);
+    });
+  }
+
+  if (!stack[n]) {
+    n = 0;
+  }
+  return stack[n] || "";
+}
+
+/**
+ * Return a stack object that can be serialized and, when
+ * deserialized, passed to callFunctionWithAsyncStack.
+ */
+function getStack() {
+  return Components.stack.caller;
+}
+
+/**
+ * Like Cu.callFunctionWithAsyncStack but handles the isWorker case
+ * -- |Cu| isn't defined in workers.
+ */
+function callFunctionWithAsyncStack(callee, stack, id) {
+  if (isWorker) {
+    return callee();
+  }
+  return Cu.callFunctionWithAsyncStack(callee, stack, id);
+}
+
+exports.callFunctionWithAsyncStack = callFunctionWithAsyncStack;
+exports.getNthPathExcluding = getNthPathExcluding;
+exports.getStack = getStack;