DirectoryBlob: Lookup DiscContents by offset + size instead of offset

This simplifies DiscContentContainer::Read.

2 files changed, 9 insertions, 8 deletions

diff --git a/Source/Core/DiscIO/DirectoryBlob.cpp b/Source/Core/DiscIO/DirectoryBlob.cpp
index e017bfca78..320d3ed054 100644
--- a/Source/Core/DiscIO/DirectoryBlob.cpp
+++ b/Source/Core/DiscIO/DirectoryBlob.cpp
@@ -77,6 +77,11 @@ u64 DiscContent::GetOffset() const
   return m_offset;
 }
 
+u64 DiscContent::GetEndOffset() const
+{
+  return m_offset + m_size;
+}
+
 u64 DiscContent::GetSize() const
 {
   return m_size;
@@ -138,13 +143,8 @@ const DiscContent& DiscContentContainer::CheckSizeAndAdd(u64 offset, u64 max_siz
 
 bool DiscContentContainer::Read(u64 offset, u64 length, u8* buffer) const
 {
-  if (m_contents.empty())
-    return true;
-
   // Determine which DiscContent the offset refers to
-  std::set<DiscContent>::const_iterator it = m_contents.lower_bound(DiscContent(offset));
-  if (it->GetOffset() > offset && it != m_contents.begin())
-    --it;
+  std::set<DiscContent>::const_iterator it = m_contents.upper_bound(DiscContent(offset));
 
   // zero fill to start of file data
   PadToAddress(it->GetOffset(), &offset, &length, &buffer);
diff --git a/Source/Core/DiscIO/DirectoryBlob.h b/Source/Core/DiscIO/DirectoryBlob.h
index 86787bbd44..4c9646ac8f 100644
--- a/Source/Core/DiscIO/DirectoryBlob.h
+++ b/Source/Core/DiscIO/DirectoryBlob.h
@@ -42,12 +42,13 @@ public:
   explicit DiscContent(u64 offset);
 
   u64 GetOffset() const;
+  u64 GetEndOffset() const;
   u64 GetSize() const;
   bool Read(u64* offset, u64* length, u8** buffer) const;
 
-  bool operator==(const DiscContent& other) const { return m_offset == other.m_offset; }
+  bool operator==(const DiscContent& other) const { return GetEndOffset() == other.GetEndOffset(); }
   bool operator!=(const DiscContent& other) const { return !(*this == other); }
-  bool operator<(const DiscContent& other) const { return m_offset < other.m_offset; }
+  bool operator<(const DiscContent& other) const { return GetEndOffset() < other.GetEndOffset(); }
   bool operator>(const DiscContent& other) const { return other < *this; }
   bool operator<=(const DiscContent& other) const { return !(*this < other); }
   bool operator>=(const DiscContent& other) const { return !(*this > other); }