Common/CDImage: Changes to support CHD interfaces

src/common/cd_image.cpp

@@ -33,6 +33,8 @@ std::unique_ptr<CDImage> CDImage::Open(const char* filename)
     return OpenCueSheetImage(filename);
   else if (CASE_COMPARE(extension, ".bin") == 0 || CASE_COMPARE(extension, ".img") == 0)
     return OpenBinImage(filename);
+  else if (CASE_COMPARE(extension, ".chd") == 0)
+    return OpenCHDImage(filename);
 
 #undef CASE_COMPARE
 
@@ -71,10 +73,6 @@ bool CDImage::Seek(LBA lba)
   if (new_index_offset >= new_index->length)
     return false;
 
-  const u64 new_file_offset = new_index->file_offset + (u64(new_index_offset) * new_index->file_sector_size);
-  if (new_index->file && std::fseek(new_index->file, static_cast<long>(new_file_offset), SEEK_SET) != 0)
-    return false;
-
   m_current_index = new_index;
   m_position_on_disc = lba;
   m_position_in_index = new_index_offset;
@@ -115,28 +113,10 @@ u32 CDImage::Read(ReadMode read_mode, u32 sector_count, void* buffer)
   u32 sectors_read = 0;
   for (; sectors_read < sector_count; sectors_read++)
   {
-    if (m_position_in_index == m_current_index->length)
-    {
-      if (!Seek(m_position_on_disc))
-        break;
-    }
-
     // get raw sector
     u8 raw_sector[RAW_SECTOR_SIZE];
-    if (m_current_index->file)
-    {
-      if (std::fread(raw_sector, RAW_SECTOR_SIZE, 1, m_current_index->file) != 1)
-      {
-        Log_ErrorPrintf("Read of LBA %u failed", m_position_on_disc);
-        Seek(m_position_on_disc);
-        return false;
-      }
-    }
-    else
-    {
-      // This in an implicit pregap. Return silence.
-      std::fill(raw_sector, raw_sector + RAW_SECTOR_SIZE, u8(0));
-    }
+    if (!ReadRawSector(raw_sector))
+      break;
 
     switch (read_mode)
     {
@@ -176,9 +156,10 @@ bool CDImage::ReadRawSector(void* buffer)
       return false;
   }
 
-  if (m_current_index->file)
+  if (m_current_index->file_sector_size > 0)
   {
-    if (std::fread(buffer, RAW_SECTOR_SIZE, 1, m_current_index->file) != 1)
+    // TODO: This is where we'd reconstruct the header for other mode tracks.
+    if (!ReadSectorFromIndex(buffer, *m_current_index, m_position_in_index))
     {
       Log_ErrorPrintf("Read of LBA %u failed", m_position_on_disc);
       Seek(m_position_on_disc);

src/common/cd_image.h

@@ -1,14 +1,11 @@
 #pragma once
 #include "bitfield.h"
 #include "types.h"
-#include <cstdio>
 #include <memory>
 #include <string>
 #include <tuple>
 #include <vector>
 
-class ByteStream;
-
 class CDImage
 {
 public:
@@ -211,7 +208,7 @@ protected:
   struct Index
   {
     u64 file_offset;
-    std::FILE* file;
+    u32 file_index;
     u32 file_sector_size;
     LBA start_lba_on_disc;
     u32 track_number;
@@ -223,6 +220,9 @@ protected:
     bool is_pregap;
   };
 
+  // Reads a single sector from an index.
+  virtual bool ReadSectorFromIndex(void* buffer, const Index& index, LBA lba_in_index) = 0;
+
   const Index* GetIndexForDiscPosition(LBA pos);
   const Index* GetIndexForTrackPosition(u32 track_number, LBA track_pos);
 

src/common/cd_image_bin.cpp

@@ -14,8 +14,12 @@ public:
 
   bool ReadSubChannelQ(SubChannelQ* subq) override;
 
+protected:
+  bool ReadSectorFromIndex(void* buffer, const Index& index, LBA lba_in_index) override;
+
 private:
   std::FILE* m_fp = nullptr;
+  u64 m_file_position = 0;
 
   CDSubChannelReplacement m_sbi;
 };
@@ -78,7 +82,7 @@ bool CDImageBin::Open(const char* filename)
 
   // Data index.
   Index data_index = {};
-  data_index.file = m_fp;
+  data_index.file_index = 0;
   data_index.file_offset = 0;
   data_index.file_sector_size = track_sector_size;
   data_index.start_lba_on_disc = pregap_index.length;
@@ -107,6 +111,27 @@ bool CDImageBin::ReadSubChannelQ(SubChannelQ* subq)
   return CDImage::ReadSubChannelQ(subq);
 }
 
+bool CDImageBin::ReadSectorFromIndex(void* buffer, const Index& index, LBA lba_in_index)
+{
+  const u64 file_position = index.file_offset + (static_cast<u64>(lba_in_index) * index.file_sector_size);
+  if (m_file_position != file_position)
+  {
+    if (std::fseek(m_fp, static_cast<long>(file_position), SEEK_SET) != 0)
+      return false;
+
+    m_file_position = file_position;
+  }
+
+  if (std::fread(buffer, index.file_sector_size, 1, m_fp) != 1)
+  {
+    std::fseek(m_fp, static_cast<long>(m_file_position), SEEK_SET);
+    return false;
+  }
+
+  m_file_position += index.file_sector_size;
+  return true;
+}
+
 std::unique_ptr<CDImage> CDImage::OpenBinImage(const char* filename)
 {
   std::unique_ptr<CDImageBin> image = std::make_unique<CDImageBin>();

src/common/cd_image_cue.cpp

@@ -18,9 +18,20 @@ public:
 
   bool ReadSubChannelQ(SubChannelQ* subq) override;
 
+protected:
+  bool ReadSectorFromIndex(void* buffer, const Index& index, LBA lba_in_index) override;
+
 private:
   Cd* m_cd = nullptr;
-  std::map<std::string, std::FILE*> m_files;
+
+  struct TrackFile
+  {
+    std::string filename;
+    std::FILE* file;
+    u64 file_position;
+  };
+
+  std::vector<TrackFile> m_files;
   CDSubChannelReplacement m_sbi;
 };
 
@@ -28,7 +39,7 @@ CDImageCueSheet::CDImageCueSheet() = default;
 
 CDImageCueSheet::~CDImageCueSheet()
 {
-  std::for_each(m_files.begin(), m_files.end(), [](const auto& it) { std::fclose(it.second); });
+  std::for_each(m_files.begin(), m_files.end(), [](TrackFile& t) { std::fclose(t.file); });
   cd_delete(m_cd);
 }
 
@@ -67,8 +78,14 @@ bool CDImageCueSheet::OpenAndParse(const char* filename)
     long track_start = track_get_start(track);
     long track_length = track_get_length(track);
 
-    auto it = m_files.find(track_filename);
-    if (it == m_files.end())
+    u32 track_file_index = 0;
+    for (; track_file_index < m_files.size(); track_file_index++)
+    {
+      const TrackFile& t = m_files[track_file_index];
+      if (t.filename == track_filename)
+        break;
+    }
+    if (track_file_index == m_files.size())
     {
       std::string track_full_filename = basepath + track_filename;
       std::FILE* track_fp = FileSystem::OpenCFile(track_full_filename.c_str(), "rb");
@@ -79,7 +96,7 @@ bool CDImageCueSheet::OpenAndParse(const char* filename)
         return false;
       }
 
-      it = m_files.emplace(track_filename, track_fp).first;
+      m_files.push_back(TrackFile{std::move(track_filename), track_fp, 0});
     }
 
     // data type determines the sector size
@@ -96,9 +113,9 @@ bool CDImageCueSheet::OpenAndParse(const char* filename)
     // determine the length from the file
     if (track_length < 0)
     {
-      std::fseek(it->second, 0, SEEK_END);
-      long file_size = std::ftell(it->second);
-      std::fseek(it->second, 0, SEEK_SET);
+      std::fseek(m_files[track_file_index].file, 0, SEEK_END);
+      long file_size = std::ftell(m_files[track_file_index].file);
+      std::fseek(m_files[track_file_index].file, 0, SEEK_SET);
 
       file_size /= track_sector_size;
       Assert(track_start < file_size);
@@ -125,7 +142,7 @@ bool CDImageCueSheet::OpenAndParse(const char* filename)
       pregap_index.is_pregap = true;
       if (pregap_in_file)
       {
-        pregap_index.file = it->second;
+        pregap_index.file_index = track_file_index;
         pregap_index.file_offset = static_cast<u64>(static_cast<s64>(track_start - pregap_frames)) * track_sector_size;
         pregap_index.file_sector_size = track_sector_size;
       }
@@ -146,7 +163,7 @@ bool CDImageCueSheet::OpenAndParse(const char* filename)
     last_index.start_lba_in_track = 0;
     last_index.track_number = track_num;
     last_index.index_number = 1;
-    last_index.file = it->second;
+    last_index.file_index = track_file_index;
     last_index.file_sector_size = track_sector_size;
     last_index.file_offset = static_cast<u64>(static_cast<s64>(track_start)) * track_sector_size;
     last_index.mode = mode;
@@ -204,6 +221,30 @@ bool CDImageCueSheet::ReadSubChannelQ(SubChannelQ* subq)
   return CDImage::ReadSubChannelQ(subq);
 }
 
+bool CDImageCueSheet::ReadSectorFromIndex(void* buffer, const Index& index, LBA lba_in_index)
+{
+  DebugAssert(index.file_index < m_files.size());
+
+  TrackFile& tf = m_files[index.file_index];
+  const u64 file_position = index.file_offset + (static_cast<u64>(lba_in_index) * index.file_sector_size);
+  if (tf.file_position != file_position)
+  {
+    if (std::fseek(tf.file, static_cast<long>(file_position), SEEK_SET) != 0)
+      return false;
+
+    tf.file_position = file_position;
+  }
+
+  if (std::fread(buffer, index.file_sector_size, 1, tf.file) != 1)
+  {
+    std::fseek(tf.file, static_cast<long>(tf.file_position), SEEK_SET);
+    return false;
+  }
+
+  tf.file_position += index.file_sector_size;
+  return true;
+}
+
 std::unique_ptr<CDImage> CDImage::OpenCueSheetImage(const char* filename)
 {
   std::unique_ptr<CDImageCueSheet> image = std::make_unique<CDImageCueSheet>();