Add PPDProvider barebones implementation and associated cache skeleton.

chromeos/printing/ppd_cache.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/files/file_util.h"
+#include "base/memory/ptr_util.h"
+#include "base/strings/stringprintf.h"
+#include "chromeos/printing/ppd_cache.h"
+
+using std::string;
+using std::unique_ptr;
+
+namespace chromeos {
+namespace printing {
+namespace {
+
+// Placeholder cache.
+class PPDCacheImpl : public PPDCache {
+ public:
+  PPDCacheImpl(const PPDCache::Options& options) : options_(options) {}
+  ~PPDCacheImpl() override {}
+
+  // Public API functions.
+  std::unique_ptr<Printer::PPDFile> Lookup(const string& manufacturer,
+                                           const string& model) const override {
+    // Not yet implemented, so everything is a cache miss.
+    return unique_ptr<Printer::PPDFile>();
+  }
+
+  // Eventually this should store the contents into the cache and return a
+  // reference to that, but for now, just store the ppd file to a temporary file
+  // and return that.
+  std::unique_ptr<Printer::PPDFile> Store(
+      const string& manufacturer,
+      const string& model,
+      int64_t time_added_ms,
+      int64_t last_updated_time_ms,
+      const string& compressed_ppd_contents) override {
+    base::FilePath contents_path = options_.cache_directory.Append(
+        ::base::StringPrintf("%s_%s.ppd", manufacturer.c_str(), model.c_str()));
+    CHECK(base::WriteFile(contents_path, compressed_ppd_contents.data(),
+                          compressed_ppd_contents.size()) > 0);
+    std::unique_ptr<Printer::PPDFile> ret(new Printer::PPDFile);

[skau, 2016/09/17 00:59:59]

ret = base::MakeUnique<PPDFile>().  Raw use of new is frowned upon now.

[Carlson, 2016/10/06 15:56:05]

Done.

+    ret->file_name = contents_path.value();
+    ret->from_quirks_server = true;
+    return ret;
+  }
+
+ private:
+  const PPDCache::Options options_;
+};
+
+}  // namespace
+
+// static
+PPDCache::Options PPDCache::Defaults() {
+  PPDCache::Options ret;
+  // TODO(justincarlson) - Set a default directory here.  Probably need to get
+  // PathService involved.
+  // TODO(justincarlson) - Should we be creating the directory if it doesn't
+  // exist?

[skau, 2016/09/17 00:59:59]

We'll need to hook back into Chrome for the directory information since it's
stored as a preference somewhere ...  Due to dependency rules, we'll probably
need to put an Options producer in chrome/browser/chromeos/printing.

[Carlson, 2016/10/06 15:56:05]

This seems to fit nicely in what PathService provides, so I've provisionally
added it there.

+  return ret;
+}
+
+// static
+unique_ptr<PPDCache> PPDCache::Create(const PPDCache::Options& options) {
+  return ::base::MakeUnique<PPDCacheImpl>(options);
+}
+
+// static
+unique_ptr<PPDCache> PPDCache::Create() {
+  return ::base::MakeUnique<PPDCacheImpl>(Defaults());
+}
+
+}  // namespace printing
+}  // namespace chromeos