[Installer] Cleaning up dead code for App Launcher / App Host installs.

chrome/installer/util/channel_info.cc

 // Copyright (c) 2012 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 "chrome/installer/util/channel_info.h"
 
 #include "base/logging.h"
 #include "base/win/registry.h"
+#include "chrome/installer/util/app_launcher_installer_util.h"
 #include "chrome/installer/util/google_update_constants.h"
+#include "chrome/installer/util/install_util.h"
 #include "chrome/installer/util/util_constants.h"
 
 using base::win::RegKey;
 
 namespace {
 
 const wchar_t kModChrome[] = L"-chrome";
 const wchar_t kModChromeFrame[] = L"-chromeframe";
-// TODO(huangs): Remove by M27.
-const wchar_t kModAppHostDeprecated[] = L"-apphost";
-const wchar_t kModAppLauncher[] = L"-applauncher";
 const wchar_t kModMultiInstall[] = L"-multi";
 const wchar_t kModReadyMode[] = L"-readymode";
 const wchar_t kModStage[] = L"-stage:";
 const wchar_t kSfxFull[] = L"-full";
 const wchar_t kSfxMigrating[] = L"-migrating";
 const wchar_t kSfxMultiFail[] = L"-multifail";
 
 const wchar_t* const kChannels[] = {
   installer::kChromeChannelBeta,
   installer::kChromeChannelDev,
   installer::kChromeChannelStableExplicit
 };
 
 const wchar_t* const kModifiers[] = {
   kModStage,
   kModMultiInstall,
   kModChrome,
   kModChromeFrame,
-  kModAppHostDeprecated,  // TODO(huangs): Remove by M27.
-  kModAppLauncher,
   kModReadyMode,
   kSfxMultiFail,
   kSfxMigrating,
   kSfxFull,
 };
 
 enum ModifierIndex {
   MOD_STAGE,
   MOD_MULTI_INSTALL,
   MOD_CHROME,
   MOD_CHROME_FRAME,
-  MOD_APP_HOST_DEPRECATED,  // TODO(huangs): Remove by M27.
-  MOD_APP_LAUNCHER,
   MOD_READY_MODE,
   SFX_MULTI_FAIL,
   SFX_MIGRATING,
   SFX_FULL,
   NUM_MODIFIERS
 };
 
 COMPILE_ASSERT(NUM_MODIFIERS == arraysize(kModifiers),
     kModifiers_disagrees_with_ModifierIndex_comma_they_must_match_bang);
 
 // Returns true if the modifier is found, in which case |position| holds the
 // location at which the modifier was found.  The number of characters in the
 // modifier is returned in |length|, if non-NULL.
 bool FindModifier(ModifierIndex index,
-                  const std::wstring& ap_value,
-                  std::wstring::size_type* position,
-                  std::wstring::size_type* length) {
+                  const base::string16& ap_value,
+                  base::string16::size_type* position,
+                  base::string16::size_type* length) {
   DCHECK(position != NULL);
-  std::wstring::size_type mod_position = std::wstring::npos;
-  std::wstring::size_type mod_length =
-      std::wstring::traits_type::length(kModifiers[index]);
+  base::string16::size_type mod_position = base::string16::npos;
+  base::string16::size_type mod_length =
+      base::string16::traits_type::length(kModifiers[index]);
   const bool mod_takes_arg = (kModifiers[index][mod_length - 1] == L':');
-  std::wstring::size_type pos = 0;
+  base::string16::size_type pos = 0;
   do {
     mod_position = ap_value.find(kModifiers[index], pos, mod_length);
-    if (mod_position == std::wstring::npos)
+    if (mod_position == base::string16::npos)
       return false;  // Modifier not found.
     pos = mod_position + mod_length;
     // Modifiers that take an argument gobble up to the next separator or to the
     // end.
     if (mod_takes_arg) {
       pos = ap_value.find(L'-', pos);
-      if (pos == std::wstring::npos)
+      if (pos == base::string16::npos)
         pos = ap_value.size();
       break;
     }
     // Regular modifiers must be followed by '-' or the end of the string.
   } while (pos != ap_value.size() && ap_value[pos] != L'-');
-  DCHECK_NE(mod_position, std::wstring::npos);
+  DCHECK_NE(mod_position, base::string16::npos);
   *position = mod_position;
   if (length != NULL)
     *length = pos - mod_position;
   return true;
 }
 
-bool HasModifier(ModifierIndex index, const std::wstring& ap_value) {
+bool HasModifier(ModifierIndex index, const base::string16& ap_value) {
   DCHECK(index >= 0 && index < NUM_MODIFIERS);
-  std::wstring::size_type position;
+  base::string16::size_type position;
   return FindModifier(index, ap_value, &position, NULL);
 }
 
-std::wstring::size_type FindInsertionPoint(ModifierIndex index,
-                                           const std::wstring& ap_value) {
+base::string16::size_type FindInsertionPoint(ModifierIndex index,
+                                             const base::string16& ap_value) {
   // Return the location of the next modifier.
-  std::wstring::size_type result;
+  base::string16::size_type result;
 
   for (int scan = index + 1; scan < NUM_MODIFIERS; ++scan) {
     if (FindModifier(static_cast<ModifierIndex>(scan), ap_value, &result, NULL))
       return result;
   }
 
   return ap_value.size();
 }
 
 // Returns true if |ap_value| is modified.
-bool SetModifier(ModifierIndex index, bool set, std::wstring* ap_value) {
+bool SetModifier(ModifierIndex index, bool set, base::string16* ap_value) {
   DCHECK(index >= 0 && index < NUM_MODIFIERS);
   DCHECK(ap_value);
-  std::wstring::size_type position;
-  std::wstring::size_type length;
+  base::string16::size_type position;
+  base::string16::size_type length;
   bool have_modifier = FindModifier(index, *ap_value, &position, &length);
   if (set) {
     if (!have_modifier) {
       ap_value->insert(FindInsertionPoint(index, *ap_value), kModifiers[index]);
       return true;
     }
   } else {
     if (have_modifier) {
       ap_value->erase(position, length);
       return true;
     }
   }
   return false;
 }
 
 }  // namespace
 
 namespace installer {
 
 bool ChannelInfo::Initialize(const RegKey& key) {
-  LONG result = key.ReadValue(google_update::kRegApField, &value_);
-  return result == ERROR_SUCCESS || result == ERROR_FILE_NOT_FOUND ||
-         result == ERROR_INVALID_HANDLE;
+  base::string16 temp_value;
+  LONG result = key.ReadValue(google_update::kRegApField, &temp_value);
+  if (result == ERROR_SUCCESS || result == ERROR_FILE_NOT_FOUND ||
+      result == ERROR_INVALID_HANDLE) {
+    set_value(temp_value);
+    return true;
+  }
+  return false;
 }
 
 bool ChannelInfo::Write(RegKey* key) const {
   DCHECK(key);
   // Google Update deletes the value when it is empty, so we may as well, too.
   LONG result = value_.empty() ?
       key->DeleteValue(google_update::kRegApField) :
       key->WriteValue(google_update::kRegApField, value_.c_str());
   if (result != ERROR_SUCCESS) {
     LOG(ERROR) << "Failed writing channel info; result: " << result;
     return false;
   }
   return true;
 }
 
-bool ChannelInfo::GetChannelName(std::wstring* channel_name) const {
+// static
+void ChannelInfo::AuditValue(base::string16* value) {
+#if defined(GOOGLE_CHROME_BUILD)
+  if (!InstallUtil::IsChromeSxSProcess()) {
+    app_launcher_installer::RemoveDeprecatedModifiers(value);
+  }
+#endif
+}
+
+const base::string16& ChannelInfo::value() const {
+  return value_;
+}
+
+void ChannelInfo::set_value(const base::string16& value) {
+  value_ = value;
+  AuditValue(&value_);

[grt (UTC plus 2), 2015/01/09 18:57:04]

i don't like how this buries magic that's specific to Chrome into a utility
class. this also breaks the ChannelInfo API. please leave ChannelInfo alone
(except for the string16 conversion, which is useful on its own) and rather
change ChromeBrowserOperations::SetChannelFlags and/or
ChromeBinariesOperations::SetChannelFlags to remove the old flags.

you could note in channel_info.h doc comments that some methods are now
deprecated.

[huangs, 2015/01/18 01:18:24]

Done: Restored channal_info.*, but set SetAppLauncher() to always remove
-applauncher.  Updated ChromeBrowserOperations() to remove the flag, and wiped
out app_launcher_install_util.cc.

[grt (UTC plus 2), 2015/01/20 21:30:22]

I don't think this is the right approach since it means that this class can no
longer be used to introspect an installation's channel. I think it's better to
have the "wipe out app host/launcher" higher up rather than have it buried in
the implementation of a utility class like this.

[huangs, 2015/01/20 23:26:00]

Okay, put back the filtering for set_value() and the unit test (not restricted
to Chrome since ChannelValue did not restrict App Launcher stuff for Chrome),
keeping all the code in channel_info*.

Not sure what to do with the ChromeBrowserOperations::SetChannelFlags() change.

[grt (UTC plus 2), 2015/01/21 02:18:12]

Let's talk in person. I must be doing a bad job of conveying what I mean in
text. The ChannelInfo implementation should not be responsible for clearing out
old values; its consumers should. I don't think ChannelInfo should be modified
much at all beyond the excellent string16 change and "deprecated" doc comments
here and there. Sorry if I'm wasting your time!

[huangs, 2015/01/21 20:33:52]

Acknowledged; restoring this per conversation.

+}
+
+bool ChannelInfo::Equals(const ChannelInfo& other) const {
+  return value_ == other.value_;
+}
+
+bool ChannelInfo::GetChannelName(base::string16* channel_name) const {
   DCHECK(channel_name);
   if (value_.empty()) {
     channel_name->erase();
     return true;
   } else {
     for (const wchar_t* const* scan = &kChannels[0],
              *const* end = &kChannels[arraysize(kChannels)]; scan != end;
          ++scan) {
-      if (value_.find(*scan) != std::wstring::npos) {
+      if (value_.find(*scan) != base::string16::npos) {
         // Report channels with "stable" in them as stable (empty string).
         if (*scan == installer::kChromeChannelStableExplicit)
           channel_name->erase();
         else
           channel_name->assign(*scan);
         return true;
       }
     }
     // There may be modifiers present.  Strip them off and see if we're left
     // with the empty string (stable channel).
-    std::wstring tmp_value = value_;
+    base::string16 tmp_value = value_;
     for (int i = 0; i != NUM_MODIFIERS; ++i) {
       SetModifier(static_cast<ModifierIndex>(i), false, &tmp_value);
     }
     if (tmp_value.empty()) {
       channel_name->erase();
       return true;
     }
   }
 
   return false;
 }
 
 bool ChannelInfo::IsChrome() const {
   return HasModifier(MOD_CHROME, value_);
 }
 
 bool ChannelInfo::SetChrome(bool value) {
   return SetModifier(MOD_CHROME, value, &value_);
 }
 
 bool ChannelInfo::IsChromeFrame() const {
   return HasModifier(MOD_CHROME_FRAME, value_);
 }
 
 bool ChannelInfo::SetChromeFrame(bool value) {
   return SetModifier(MOD_CHROME_FRAME, value, &value_);
 }
 
-bool ChannelInfo::IsAppLauncher() const {
-  return HasModifier(MOD_APP_LAUNCHER, value_);
-}
-
-bool ChannelInfo::SetAppLauncher(bool value) {
-  // Unconditionally remove -apphost since it has been deprecated.
-  bool changed_app_host = SetModifier(MOD_APP_HOST_DEPRECATED, false, &value_);
-  bool changed_app_launcher = SetModifier(MOD_APP_LAUNCHER, value, &value_);
-  return changed_app_host || changed_app_launcher;
-}
-
 bool ChannelInfo::IsMultiInstall() const {
   return HasModifier(MOD_MULTI_INSTALL, value_);
 }
 
 bool ChannelInfo::SetMultiInstall(bool value) {
   return SetModifier(MOD_MULTI_INSTALL, value, &value_);
 }
 
 bool ChannelInfo::IsReadyMode() const {
   return HasModifier(MOD_READY_MODE, value_);
 }
 
 bool ChannelInfo::SetReadyMode(bool value) {
   return SetModifier(MOD_READY_MODE, value, &value_);
 }
 
 bool ChannelInfo::SetStage(const wchar_t* stage) {
-  std::wstring::size_type position;
-  std::wstring::size_type length;
+  base::string16::size_type position;
+  base::string16::size_type length;
   bool have_modifier = FindModifier(MOD_STAGE, value_, &position, &length);
   if (stage != NULL && *stage != L'\0') {
-    std::wstring stage_str(kModStage);
+    base::string16 stage_str(kModStage);
     stage_str.append(stage);
     if (!have_modifier) {
       value_.insert(FindInsertionPoint(MOD_STAGE, value_), stage_str);
       return true;
     }
     if (value_.compare(position, length, stage_str) != 0) {
       value_.replace(position, length, stage_str);
       return true;
     }
   } else {
     if (have_modifier) {
       value_.erase(position, length);
       return true;
     }
   }
   return false;
 }
 
-std::wstring ChannelInfo::GetStage() const {
-  std::wstring::size_type position;
-  std::wstring::size_type length;
+base::string16 ChannelInfo::GetStage() const {
+  base::string16::size_type position;
+  base::string16::size_type length;
 
   if (FindModifier(MOD_STAGE, value_, &position, &length)) {
     // Return the portion after the prefix.
-    std::wstring::size_type pfx_length =
-        std::wstring::traits_type::length(kModStage);
+    base::string16::size_type pfx_length =
+        base::string16::traits_type::length(kModStage);
     DCHECK_LE(pfx_length, length);
     return value_.substr(position + pfx_length, length - pfx_length);
   }
-  return std::wstring();
+  return base::string16();
 }
 
 bool ChannelInfo::HasFullSuffix() const {
   return HasModifier(SFX_FULL, value_);
 }
 
 bool ChannelInfo::SetFullSuffix(bool value) {
   return SetModifier(SFX_FULL, value, &value_);
 }
 
@@ skipping 18 matching lines @@
 
   for (int scan = 0; scan < NUM_MODIFIERS; ++scan) {
     ModifierIndex index = static_cast<ModifierIndex>(scan);
     modified = SetModifier(index, false, &value_) || modified;
   }
 
   return modified;
 }
 
 }  // namespace installer