[NaCl SDK] Expose Google Drive to nacl_io.

native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs_util.cc

Index: native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs_util.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs_util.cc b/native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs_util.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7c34456fc689b676e3329bc54b11c6ad64b28931
--- /dev/null
+++ b/native_client_sdk/src/libraries/nacl_io/googledrivefs/googledrivefs_util.cc
@@ -0,0 +1,425 @@
+// Copyright (c) 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 "nacl_io/googledrivefs/googledrivefs_util.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "ppapi/c/pp_completion_callback.h"
+
+#include "nacl_io/error.h"
+#include "nacl_io/filesystem.h"
+#include "nacl_io/path.h"
+#include "nacl_io/pepper_interface.h"
+#include "nacl_io/statuscode.h"
+#include "nacl_io/googledrivefs/googledrivefs.h"
+
+namespace nacl_io {
+
+std::string ParentEqualClause(const std::string& parent_dir_id) {
+  return "%27" + parent_dir_id + "%27+in+parents";
+}
+
+std::string NameEqualClause(const std::string& name) {
+  return "name+=+%27" + name + "%27";
+}
+
+int ExtractYearFromRFC3339(const std::string& date_time) {
+  return atoi(date_time.substr(0, 4).c_str());
+}
+
+int ExtractMonthFromRFC3339(const std::string& date_time) {
+  return atoi(date_time.substr(5, 2).c_str());
+}
+
+int ExtractDayFromRFC3339(const std::string& date_time) {
+  return atoi(date_time.substr(8, 2).c_str());
+}
+
+int ExtractHourFromRFC3339(const std::string& date_time) {
+  return atoi(date_time.substr(11, 2).c_str());
+}
+
+int ExtractMinuteFromRFC3339(const std::string& date_time) {
+  return atoi(date_time.substr(14, 2).c_str());
+}
+
+int ExtractSecondFromRFC3339(const std::string& date_time) {
+  return atoi(date_time.substr(17, 2).c_str());
+}
+
+time_t ConvertDateTimeToEpochTime(int year,
+                                  int month,
+                                  int day,
+                                  int hour,
+                                  int minute,
+                                  int second) {
+  time_t epoch_time = 0;
+
+  for (int i = 1970; i < year; ++i) {
+    if (i % 4 == 0 && (i % 100 != 0 || i % 400 == 0)) {
+      epoch_time += 366 * 24 * 60 * 60;
+    } else {
+      epoch_time += 365 * 24 * 60 * 60;
+    }
+  }
+  int month_to_number_of_days[] = {31, 28, 31, 30, 31, 30,
+                                   31, 31, 30, 31, 30, 31};
+
+  for (int i = 1; i < month; ++i) {
+    epoch_time += month_to_number_of_days[i - 1] * 24 * 60 * 60;
+    if (i == 2 && (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0))) {
+      epoch_time += 24 * 60 * 60;
+    }
+  }
+
+  epoch_time += (day - 1) * 24 * 60 * 60;
+
+  if (hour > 0) {
+    epoch_time += hour * 60 * 60;
+  }
+
+  if (minute > 0) {
+    epoch_time += minute * 60;
+  }
+
+  epoch_time += second;
+
+  return epoch_time;
+}
+
+void AddUrlPath(const std::string& path, std::string* out_url) {
+  *out_url += "/";
+  *out_url += path;
+}
+
+void AddUrlQAttributeValue(std::string* array,
+                           size_t size,
+                           std::string* out_q_attribute_value) {
+  *out_q_attribute_value = array[0];
+  for (size_t i = 1; i < size; ++i) {
+    *out_q_attribute_value += "+and+";
+    *out_q_attribute_value += array[i];
+  }
+}
+
+void AddUrlFirstQueryParameter(const std::string& attribute,
+                               const std::string& value,
+                               std::string* out_url) {
+  *out_url += "?";
+  *out_url += attribute;
+  *out_url += "=";
+  *out_url += value;
+}
+
+void AddUrlNextQueryParameter(const std::string& attribute,
+                              const std::string& value,
+                              std::string* out_url) {
+  *out_url += "&";
+  *out_url += attribute;
+  *out_url += "=";
+  *out_url += value;
+}
+
+void AddHeaders(const std::string& header_field_key,
+                const std::string& header_field_value,
+                std::string* out_headers) {
+  *out_headers += header_field_key;
+  *out_headers += ": ";
+  *out_headers += header_field_value;
+  *out_headers += "\n";
+}
+
+void AddBody(const std::string& data, std::string* out_body) {
+  *out_body += data;
+  *out_body += "\n";
+}
+
+Error LoadUrl(PepperInterface* ppapi,
+              const RequestUrlParams& params,
+              ScopedResource* out_url_response_info_resource) {
+  out_url_response_info_resource->Reset(0);
+
+  URLLoaderInterface* url_loader_iface = ppapi->GetURLLoaderInterface();
+  ScopedResource url_loader_resource(
+      ppapi, url_loader_iface->Create(ppapi->GetInstance()));
+  if (!url_loader_resource.pp_resource()) {
+    return EPERM;
+  }
+
+  URLRequestInfoInterface* url_request_info_iface =
+      ppapi->GetURLRequestInfoInterface();
+  ScopedResource url_request_info_resource(
+      ppapi, url_request_info_iface->Create(ppapi->GetInstance()));
+  if (!url_request_info_resource.pp_resource()) {
+    return EPERM;
+  }
+
+  VarInterface* var_iface = ppapi->GetVarInterface();
+
+  struct PP_Var pp_var =
+      var_iface->VarFromUtf8(params.url.c_str(), params.url.size());
+  if (!url_request_info_iface->SetProperty(
+          url_request_info_resource.pp_resource(), PP_URLREQUESTPROPERTY_URL,
+          pp_var)) {
+    return EPERM;
+  }
+
+  pp_var = var_iface->VarFromUtf8(params.method.c_str(), params.method.size());
+  if (!url_request_info_iface->SetProperty(
+          url_request_info_resource.pp_resource(), PP_URLREQUESTPROPERTY_METHOD,
+          pp_var)) {
+    return EPERM;
+  }
+
+  pp_var =
+      var_iface->VarFromUtf8(params.headers.c_str(), params.headers.size());
+  if (!url_request_info_iface->SetProperty(
+          url_request_info_resource.pp_resource(),
+          PP_URLREQUESTPROPERTY_HEADERS, pp_var)) {
+    return EPERM;
+  }
+
+  if (!url_request_info_iface->AppendDataToBody(
+          url_request_info_resource.pp_resource(), params.body.data(),
+          params.body.size())) {
+    return EPERM;
+  }
+
+  pp_var = PP_MakeBool(PP_TRUE);
+  if (!url_request_info_iface->SetProperty(
+          url_request_info_resource.pp_resource(),
+          PP_URLREQUESTPROPERTY_ALLOWCROSSORIGINREQUESTS, pp_var)) {
+    return EPERM;
+  }
+
+  pp_var = PP_MakeBool(PP_TRUE);
+  if (!url_request_info_iface->SetProperty(
+          url_request_info_resource.pp_resource(),
+          PP_URLREQUESTPROPERTY_STREAMTOFILE, pp_var)) {
+    return EPERM;
+  }
+
+  int32_t err = url_loader_iface->Open(url_loader_resource.pp_resource(),
+                                       url_request_info_resource.pp_resource(),
+                                       PP_BlockUntilComplete());
+  if (err < 0) {
+    return PPERROR_TO_ERRNO(err);
+  }
+
+  int32_t bytes_read = url_loader_iface->FinishStreamingToFile(
+      url_loader_resource.pp_resource(), PP_BlockUntilComplete());
+  if (bytes_read < 0) {
+    return PPERROR_TO_ERRNO(bytes_read);
+  }
+
+  out_url_response_info_resource->Reset(
+      url_loader_iface->GetResponseInfo(url_loader_resource.pp_resource()));
+  if (!out_url_response_info_resource->pp_resource()) {
+    return EPERM;
+  }
+

[chanpatorikku, 2016/08/29 17:14:04]

Not calling 

url_loader_iface->Close(url_loader_object);

as in patch set 2. 

ScopedResource looks to be able to release resource automatically, as shown in
http_fs_node.cc and fake_resource_manager.cc. Close(..) is not called to release
resources.

+  return 0;
+}
+
+Error ReadResponseBody(PepperInterface* ppapi,
+                       PP_Resource url_response_info_object,
+                       uint32_t bytes_to_read,
+                       std::string* out_output) {
+  out_output->clear();
+
+  URLResponseInfoInterface* url_response_info_iface =
+      ppapi->GetURLResponseInfoInterface();
+  FileIoInterface* file_io_iface = ppapi->GetFileIoInterface();
+
+  ScopedResource file_ref_resource(
+      ppapi,
+      url_response_info_iface->GetBodyAsFileRef(url_response_info_object));
+  if (!file_ref_resource.pp_resource()) {
+    return EPERM;
+  }
+
+  ScopedResource file_io_resource(ppapi,
+                                  file_io_iface->Create(ppapi->GetInstance()));
+  if (!file_io_resource.pp_resource()) {
+    return EPERM;
+  }
+
+  int32_t open_result = file_io_iface->Open(
+      file_io_resource.pp_resource(), file_ref_resource.pp_resource(),
+      PP_FILEOPENFLAG_READ, PP_BlockUntilComplete());
+  if (open_result < 0) {
+    return PPERROR_TO_ERRNO(open_result);
+  }
+
+  std::string string_buffer(1024, '\0');

[binji, 2016/08/30 01:39:35]

Use std::vector instead of std::string for raw data.

[chanpatorikku, 2016/09/06 14:49:38]

std::string can handle raw data.

There're cases when the type uint8_t is better than the type char for storing an
element of raw data, but for GoogleDriveFs such cases do not arise.

[binji, 2016/09/20 01:22:04]

Yes, you can use std::string; it's not guaranteed to be contiguous, but in
practice it is. But why? std::string is designed to handle text, but it seems
you are using it to read and manipulate bytes. Using std::vector better conveys
the intent.

[chanpatorikku, 2016/09/21 16:41:09]

Code not changing.

The reason is that the buffer argument of PPB_FileIO::Read is char*.

int32_t(* PPB_FileIO::Read)(PP_Resource file_io, int64_t offset, char *buffer,
int32_t bytes_to_read, struct PP_CompletionCallback callback)

std::string can be rewritten as std::vector<char>, but std::vector<char> and
std::string are very similar.

+  int32_t bytes_read =
+      file_io_iface->Read(file_io_resource.pp_resource(), 0, &string_buffer[0],
+                          string_buffer.size(), PP_BlockUntilComplete());
+
+  while (bytes_read > 0) {
+    *out_output += string_buffer.substr(0, bytes_read);
+
+    bytes_read = file_io_iface->Read(
+        file_io_resource.pp_resource(), out_output->size(), &string_buffer[0],
+        string_buffer.size(), PP_BlockUntilComplete());
+  }
+
+  if (bytes_read < 0) {
+    return PPERROR_TO_ERRNO(bytes_read);
+  }
+
+  out_output->resize(std::min<size_t>(out_output->size(), bytes_to_read));
+
+  return 0;
+}
+
+int32_t ReadStatusCode(PepperInterface* ppapi,
+                       PP_Resource url_response_info_object) {
+  URLResponseInfoInterface* url_response_info_iface =
+      ppapi->GetURLResponseInfoInterface();
+
+  struct PP_Var status_code_var = url_response_info_iface->GetProperty(
+      url_response_info_object, PP_URLRESPONSEPROPERTY_STATUSCODE);
+
+  return status_code_var.value.as_int;
+}
+
+Error GetValueStringAndValuePos(const std::string& json,
+                                const std::string& key,
+                                size_t key_search_pos,
+                                std::string* out_value_string,
+                                size_t* out_value_pos) {
+  out_value_string->clear();
+  *out_value_pos = std::string::npos;
+
+  // json format is
+  // ..
+  // "<key1>": "<value1>"
+  // ..
+  // "<key2>": "<value2>"
+  // ..
+  // The variable key_location stores the index of the first character
+  // of a target key.
+  const char* s_quote_colon_quote = "\": \"";
+  size_t key_location = json.find(key + s_quote_colon_quote, key_search_pos);
+  if (key_location == std::string::npos) {
+    return EINVAL;
+  }
+
+  size_t start_value_index =
+      key_location + key.size() + strlen(s_quote_colon_quote);
+  size_t end_value_index = json.find("\"", start_value_index);
+  if (end_value_index == std::string::npos) {
+    return EPERM;
+  }
+
+  *out_value_string =
+      json.substr(start_value_index, end_value_index - start_value_index);
+  *out_value_pos = start_value_index;
+
+  return 0;
+}
+
+// A Google Drive item is a file or a directory.
+// RequestItemIdAndItemType requests to see if either a file
+// with item_name or a directory with item_name is there.
+Error RequestItemIdAndItemType(const std::string& parent_dir_id,
+                               const std::string& item_name,
+                               Filesystem* filesystem,
+                               std::string* out_item_id,
+                               bool* out_is_dir_type) {
+  out_item_id->clear();
+  *out_is_dir_type = false;
+
+  GoogleDriveFs* googledrivefs = static_cast<GoogleDriveFs*>(filesystem);
+
+  RequestUrlParams p;
+
+  p.url = DRIVE_URL;
+  std::string q_attribute_value;
+  std::string attribute_values[] = {ParentEqualClause(parent_dir_id),
+                                    NameEqualClause(item_name)};
+
+  AddUrlQAttributeValue(attribute_values,
+                        NACL_ARRAY_SIZE_UNSAFE(attribute_values),

[chanpatorikku, 2016/08/29 17:14:04]

NACL_ARRAY_SIZE_UNSAFE(arr) borrows from
native_client/src/include/nacl_macros.h.

In native_client/src/include/nacl_macros.h, the safe version of NACL_ARRAY_SIZE
is defined in a complicated way and depends on _MSC_VER and __GNUC__.

If you would like the complete macro specified in nacl_macros.h to be copied to,
for example, native_client_sdk/src/libraries/sdk_util/macros.h, please let me
know.

[binji, 2016/08/30 01:39:35]

This definition is fine. Also, don't use the NACL_ prefix, it would be better to
use NACL_IO_ or move it into the .cc file if possible and remove the prefix.

[chanpatorikku, 2016/09/06 14:49:38]

Done.

Moved the macro into the .cc file if possible and removed the prefix.

+                        &q_attribute_value);
+  AddUrlFirstQueryParameter("q", q_attribute_value, &p.url);
+
+  p.method = "GET";
+
+  AddHeaders("Content-type", "application/json", &p.headers);
+  AddHeaders("Authorization", "Bearer " + googledrivefs->token(), &p.headers);
+
+  ScopedResource url_response_info_resource(googledrivefs->ppapi());
+  Error error = LoadUrl(googledrivefs->ppapi(), p, &url_response_info_resource);
+  if (error) {
+    return error;
+  }
+
+  if (ReadStatusCode(googledrivefs->ppapi(),
+                     url_response_info_resource.pp_resource()) !=
+      STATUSCODE_OK) {
+    return EPERM;
+  }
+
+  std::string output;
+  error = ReadResponseBody(googledrivefs->ppapi(),
+                           url_response_info_resource.pp_resource(), UINT_MAX,
+                           &output);
+  if (error) {
+    return error;
+  }
+
+  size_t id_index;
+  error = GetValueStringAndValuePos(output, "id", 0, out_item_id, &id_index);
+  if (error == EINVAL) {
+    return ENOENT;
+  } else if (error) {
+    return error;
+  }
+
+  std::string mime_type_value;
+  size_t mime_type_index;
+  error = GetValueStringAndValuePos(output, "mimeType", 0, &mime_type_value,
+                                    &mime_type_index);
+  if (error) {
+    return EPERM;
+  }
+
+  *out_is_dir_type = (mime_type_value == FOLDER_MIME_TYPE);
+
+  return 0;
+}
+
+Error RequestParentDirId(const Path& path,
+                         Filesystem* filesystem,
+                         std::string* out_parent_dir_id) {
+  out_parent_dir_id->clear();
+
+  if (path.IsRoot()) {
+    return EINVAL;
+  }
+
+  std::string helper_parent_dir_id = "root";
+
+  for (size_t i = 1; i < path.Size() - 1; ++i) {
+    std::string dir_name = path.Range(i, i + 1);
+    std::string dir_id;
+    bool is_dir_type;
+    Error error = RequestItemIdAndItemType(helper_parent_dir_id, dir_name,
+                                           filesystem, &dir_id, &is_dir_type);
+    if (error || !is_dir_type) {
+      return EPERM;
+    }
+
+    helper_parent_dir_id = dir_id;
+  }
+  *out_parent_dir_id = helper_parent_dir_id;
+
+  return 0;
+}
+
+}  // namespace nacl_io