Add ProcessSnapshotMinidump, the beginning of the minidump variant of the Snapshot family

snapshot/minidump/minidump_simple_string_dictionary_reader.cc

Index: snapshot/minidump/minidump_simple_string_dictionary_reader.cc
diff --git a/snapshot/minidump/minidump_simple_string_dictionary_reader.cc b/snapshot/minidump/minidump_simple_string_dictionary_reader.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2f2189ba57338460e30fc5565c74e1b88101d184
--- /dev/null
+++ b/snapshot/minidump/minidump_simple_string_dictionary_reader.cc
@@ -0,0 +1,102 @@
+// Copyright 2015 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "snapshot/minidump/minidump_simple_string_dictionary_reader.h"
+
+#include <vector>
+#include <utility>
+
+#include "base/logging.h"
+#include "minidump/minidump_extensions.h"
+#include "snapshot/minidump/minidump_string_reader.h"
+
+namespace crashpad {
+namespace internal {
+
+bool ReadMinidumpSimpleStringDictionary(
+    FileReaderInterface* file_reader,
+    const MINIDUMP_LOCATION_DESCRIPTOR& location,
+    std::map<std::string, std::string>* dictionary) {
+  if (location.Rva == 0) {
+    dictionary->clear();
+    return true;
+  }
+
+  if (location.DataSize < sizeof(MinidumpSimpleStringDictionary)) {
+    LOG(ERROR) << "simple_string_dictionary size mismatch";
+    return false;
+  }
+
+  FileOffset original_offset = file_reader->SeekGet();
+  if (original_offset < 0) {
+    return false;
+  }
+
+  if (!file_reader->SeekSet(location.Rva)) {
+    return false;
+  }
+
+  MinidumpSimpleStringDictionary simple_string_dictionary_base;
+  if (!file_reader->ReadExactly(&simple_string_dictionary_base,
+                                sizeof(simple_string_dictionary_base))) {
+    return false;
+  }
+
+  if (location.DataSize !=
+      simple_string_dictionary_base.count *
+          sizeof(simple_string_dictionary_base.entries[0])) {
+    LOG(ERROR) << "simple_string_dictionary size mismatch";
+    return false;
+  }
+
+  std::vector<MinidumpSimpleStringDictionaryEntry> entries(
+      simple_string_dictionary_base.count);
+  if (!file_reader->ReadExactly(
+          &entries[0],
+          simple_string_dictionary_base.count * sizeof(entries[0]))) {
+    return false;
+  }
+
+  std::map<std::string, std::string> local_dictionary;
+  for (const MinidumpSimpleStringDictionaryEntry& entry : entries) {
+    std::string key;
+    if (!ReadMinidumpUTF8String(file_reader, entry.key, &key)) {
+      // Not a hard error, keep trying.
+      continue;
+    }
+
+    std::string value;
+    if (!ReadMinidumpUTF8String(file_reader, entry.value, &value)) {
+      // Not a hard error, keep trying.
+      continue;
+    }
+
+    if (local_dictionary.find(key) != local_dictionary.end()) {
+      LOG(WARNING) << "duplicate key " << key << ", discarding value " << value;
+      continue;
+    }
+
+    local_dictionary.insert(std::make_pair(key, value));
+  }
+
+  if (!file_reader->SeekSet(original_offset)) {
+    return false;
+  }
+
+  dictionary->swap(local_dictionary);
+  return true;
+}
+
+}  // namespace internal
+}  // namespace crashpad