Register factory functions with DirManager to interpret XML tags...

... Removes direct dependency on ODManager.h and some BlockFile subclasses,
but does not yet break any dependency cycles

src/DirManager.cpp

@@ -86,9 +86,6 @@
 #endif
 
 #include "FileNames.h"
-#include "blockfile/LegacyBlockFile.h"
-#include "blockfile/LegacyAliasBlockFile.h"
-#include "blockfile/SilentBlockFile.h"
 #include "blockfile/ODPCMAliasBlockFile.h"
 #include "blockfile/ODDecodeBlockFile.h"
 #include "InconsistencyException.h"
@@ -98,8 +95,6 @@
 #include "widgets/ErrorDialog.h"
 #include "widgets/ProgressDialog.h"
 
-#include "ondemand/ODManager.h"
-
 #if defined(__WXMAC__)
 #include <mach/mach.h>
 #include <mach/vm_statistics.h>
@@ -1340,6 +1335,24 @@ BlockFilePtr DirManager::CopyBlockFile(const BlockFilePtr &b)
    return b2;
 }
 
+namespace {
+
+using Deserializers =
+   std::unordered_map< wxString, DirManager::BlockFileDeserializer >;
+Deserializers &GetDeserializers()
+{
+   static Deserializers sDeserializers;
+   return sDeserializers;
+}
+
+}
+
+DirManager::RegisteredBlockFileDeserializer::RegisteredBlockFileDeserializer(
+   const wxString &tag, BlockFileDeserializer function )
+{
+   GetDeserializers()[tag] = function;
+}
+
 bool DirManager::HandleXMLTag(const wxChar *tag, const wxChar **attrs)
 {
    if( !mLoadingTarget )
@@ -1350,60 +1363,21 @@ bool DirManager::HandleXMLTag(const wxChar *tag, const wxChar **attrs)
    BlockFilePtr &target = mLoadingTarget();
    mLoadingTarget = nullptr;
    
-   if (!wxStricmp(tag, wxT("silentblockfile"))) {
+   auto &table = GetDeserializers();
-      // Silent blocks don't actually have a file associated, so
+   auto iter = table.find( tag );
-      // we don't need to worry about the hash table at all
+   if ( iter == table.end() )
-      target = SilentBlockFile::BuildFromXML(*this, attrs);
-      return true;
-   }
-   else if ( !wxStricmp(tag, wxT("simpleblockfile")) )
-      pBlockFile = SimpleBlockFile::BuildFromXML(*this, attrs);
-   else if( !wxStricmp(tag, wxT("pcmaliasblockfile")) )
-      pBlockFile = PCMAliasBlockFile::BuildFromXML(*this, attrs);
-   else if( !wxStricmp(tag, wxT("odpcmaliasblockfile")) )
-   {
-      pBlockFile = ODPCMAliasBlockFile::BuildFromXML(*this, attrs);
-      //in the case of loading an OD file, we need to schedule the ODManager to begin OD computing of summary
-      //However, because we don't have access to the track or even the Sequence from this call, we mark a flag
-      //in the ODMan and check it later.
-      ODManager::MarkLoadedODFlag();
-   }
-   else if( !wxStricmp(tag, wxT("oddecodeblockfile")) )
-   {
-      pBlockFile = ODDecodeBlockFile::BuildFromXML(*this, attrs);
-      ODManager::MarkLoadedODFlag();
-   }
-   else if( !wxStricmp(tag, wxT("blockfile")) ||
-            !wxStricmp(tag, wxT("legacyblockfile")) ) {
-      // Support Audacity version 1.1.1 project files
-
-      int i=0;
-      bool alias = false;
-
-      while(attrs[i]) {
-         if (!wxStricmp(attrs[i], wxT("alias"))) {
-            if (wxAtoi(attrs[i+1])==1)
-               alias = true;
-         }
-         i++;
-         if (attrs[i])
-            i++;
-      }
-
-      if (alias)
-         pBlockFile = LegacyAliasBlockFile::BuildFromXML(projFull, attrs);
-      else
-         pBlockFile = LegacyBlockFile::BuildFromXML(projFull, attrs,
-                                                         mLoadingBlockLen,
-                                                         mLoadingFormat);
-   }
-   else
       return false;
+   pBlockFile = iter->second( *this, attrs );
 
    if (!pBlockFile)
       // BuildFromXML failed, or we didn't find a valid blockfile tag.
       return false;
 
+   if (!pBlockFile->GetFileName().name.IsOk())
+     // Silent blocks don't actually have a file associated, so
+     // we don't need to worry about the hash table at all
+     return true;
+
    // Check the length here so we don't have to do it in each BuildFromXML method.
    if ((mMaxSamples != ~size_t(0)) && // is initialized
          (pBlockFile->GetLength() > mMaxSamples))

src/DirManager.h

@@ -68,6 +68,16 @@ class PROFILE_DLL_API DirManager final : public XMLTagHandler {
    static void RecursivelyRemove(const FilePaths& filePathArray, int count, int bias,
                                  int flags, const wxChar* message = nullptr);
 
+   // Type of a function that builds a block file, using attributes from XML
+   using BlockFileDeserializer =
+      std::function< BlockFilePtr( DirManager&, const wxChar ** ) >;
+   // Typically a statically declared object,
+   // registers a function for an XML tag
+   struct RegisteredBlockFileDeserializer {
+      RegisteredBlockFileDeserializer(
+         const wxString &tag, BlockFileDeserializer function );
+   };
+
  private:
    // MM: Construct DirManager
    // Don't call this directly but use Create() instead
@@ -162,7 +172,9 @@ class PROFILE_DLL_API DirManager final : public XMLTagHandler {
    {
       mLoadingTarget = loadingTarget;
    }
+   sampleFormat GetLoadingFormat() const { return mLoadingFormat; }
    void SetLoadingFormat(sampleFormat format) { mLoadingFormat = format; }
+   size_t GetLoadingBlockLength() const { return mLoadingBlockLen; }
    void SetLoadingBlockLength(size_t len) { mLoadingBlockLen = len; }
 
    // Note: following affects only the loading of block files when opening a project

src/blockfile/LegacyAliasBlockFile.cpp

@@ -17,6 +17,7 @@
 #include <sndfile.h>
 
 #include "LegacyBlockFile.h"
+#include "../DirManager.h"
 #include "../FileFormats.h"
 #include "../xml/XMLTagHandler.h"
 
@@ -147,3 +148,36 @@ BlockFilePtr LegacyAliasBlockFile::BuildFromXML(const FilePath &projDir, const w
 void LegacyAliasBlockFile::Recover(){
    WriteSummary();
 }
+
+static const auto sFactory = []( DirManager &dm, const wxChar **attrs ){
+
+   // Support Audacity version 1.1.1 project files
+
+   int i=0;
+   bool alias = false;
+
+   while(attrs[i]) {
+      if (!wxStricmp(attrs[i], wxT("alias"))) {
+         if (wxAtoi(attrs[i+1])==1)
+            alias = true;
+      }
+      i++;
+      if (attrs[i])
+         i++;
+   }
+
+   if (alias)
+      return LegacyAliasBlockFile::BuildFromXML(
+         dm.GetProjectDataDir(), attrs);
+   else
+      return LegacyBlockFile::BuildFromXML(dm.GetProjectDataDir(), attrs,
+         dm.GetLoadingBlockLength(),
+         dm.GetLoadingFormat());
+};
+
+static DirManager::RegisteredBlockFileDeserializer sRegistration1 {
+   "blockfile", sFactory
+};
+static DirManager::RegisteredBlockFileDeserializer sRegistration2 {
+   "legacyblockfile", sFactory
+};

src/blockfile/ODDecodeBlockFile.cpp

@@ -29,6 +29,7 @@ The summary is eventually computed and written to a file in a background thread.
 
 #include "../DirManager.h"
 #include "../FileFormats.h"
+#include "../ondemand/ODManager.h"
 #include "NotYetAvailableException.h"
 
 const int bheaderTagLen = 20;
@@ -524,3 +525,11 @@ void ODDecodeBlockFile::ChangeAudioFile(wxFileNameWrapper &&newAudioFile)
 
 
 
+static DirManager::RegisteredBlockFileDeserializer sRegistration {
+   "oddecodeblockfile",
+   []( DirManager &dm, const wxChar **attrs ){
+      auto result = ODDecodeBlockFile::BuildFromXML( dm, attrs );
+      ODManager::MarkLoadedODFlag();
+      return result;
+   }
+};

src/blockfile/ODPCMAliasBlockFile.cpp

@@ -561,4 +561,15 @@ void ODPCMAliasBlockFile::UnlockRead() const
    mReadDataMutex.Unlock();
 }
 
+static DirManager::RegisteredBlockFileDeserializer sRegistration {
+   "odpcmaliasblockfile",
+   []( DirManager &dm, const wxChar **attrs ){
+      auto result = ODPCMAliasBlockFile::BuildFromXML( dm, attrs );
+      //in the case of loading an OD file, we need to schedule the ODManager to begin OD computing of summary
+      //However, because we don't have access to the track or even the Sequence from this call, we mark a flag
+      //in the ODMan and check it later.
+      ODManager::MarkLoadedODFlag();
+      return result;
+   }
+};
 

src/blockfile/PCMAliasBlockFile.cpp

@@ -200,3 +200,9 @@ void PCMAliasBlockFile::Recover(void)
    WriteSummary();
 }
 
+static DirManager::RegisteredBlockFileDeserializer sRegistration {
+   "pcmaliasblockfile",
+   []( DirManager &dm, const wxChar **attrs ){
+      return PCMAliasBlockFile::BuildFromXML( dm, attrs );
+   }
+};

src/blockfile/SilentBlockFile.cpp

@@ -12,6 +12,7 @@
 #include "SilentBlockFile.h"
 
 #include "../FileFormats.h"
+#include "../DirManager.h"
 #include "../xml/XMLTagHandler.h"
 
 SilentBlockFile::SilentBlockFile(size_t sampleLen):
@@ -91,3 +92,9 @@ auto SilentBlockFile::GetSpaceUsage() const -> DiskByteCount
    return 0;
 }
 
+static DirManager::RegisteredBlockFileDeserializer sRegistration {
+   "silentblockfile",
+   []( DirManager &dm, const wxChar **attrs ){
+      return SilentBlockFile::BuildFromXML( dm, attrs );
+   }
+};

src/blockfile/SimpleBlockFile.cpp

@@ -610,3 +610,10 @@ bool SimpleBlockFile::GetCache()
    return false;
 #endif
 }
+
+static DirManager::RegisteredBlockFileDeserializer sRegistration {
+   "simpleblockfile",
+   []( DirManager &dm, const wxChar **attrs ){
+      return SimpleBlockFile::BuildFromXML( dm, attrs );
+   }
+};