diff options
Diffstat (limited to 'src/core/file_sys/vfs_concat.cpp')
-rw-r--r-- | src/core/file_sys/vfs_concat.cpp | 39 |
1 files changed, 26 insertions, 13 deletions
diff --git a/src/core/file_sys/vfs_concat.cpp b/src/core/file_sys/vfs_concat.cpp index dc7a279a9..0c07e162e 100644 --- a/src/core/file_sys/vfs_concat.cpp +++ b/src/core/file_sys/vfs_concat.cpp @@ -5,10 +5,22 @@ #include <algorithm> #include <utility> +#include "common/assert.h" #include "core/file_sys/vfs_concat.h" namespace FileSys { +bool VerifyConcatenationMap(std::map<u64, VirtualFile> map) { + for (auto iter = map.begin(); iter != --map.end();) { + const auto old = iter++; + if (old->first + old->second->GetSize() != iter->first) { + return false; + } + } + + return map.begin()->first == 0; +} + VirtualFile ConcatenateFiles(std::vector<VirtualFile> files, std::string name) { if (files.empty()) return nullptr; @@ -27,7 +39,10 @@ ConcatenatedVfsFile::ConcatenatedVfsFile(std::vector<VirtualFile> files_, std::s } } -ConcatenatedVfsFile::~ConcatenatedVfsFile() = default; +ConcatenatedVfsFile::ConcatenatedVfsFile(std::map<u64, VirtualFile> files_, std::string name) + : files(std::move(files_)), name(std::move(name)) { + ASSERT(VerifyConcatenationMap(files)); +} std::string ConcatenatedVfsFile::GetName() const { if (files.empty()) @@ -62,28 +77,25 @@ bool ConcatenatedVfsFile::IsReadable() const { } std::size_t ConcatenatedVfsFile::Read(u8* data, std::size_t length, std::size_t offset) const { - auto entry = files.end(); + std::pair<u64, VirtualFile> entry = *files.rbegin(); for (auto iter = files.begin(); iter != files.end(); ++iter) { if (iter->first > offset) { - entry = --iter; + entry = *--iter; break; } } - // Check if the entry should be the last one. The loop above will make it end(). - if (entry == files.end() && offset < files.rbegin()->first + files.rbegin()->second->GetSize()) - --entry; - - if (entry == files.end()) + if (entry.first + entry.second->GetSize() <= offset) return 0; - const auto remaining = entry->second->GetSize() + offset - entry->first; - if (length > remaining) { - return entry->second->Read(data, remaining, offset - entry->first) + - Read(data + remaining, length - remaining, offset + remaining); + const auto read_in = + std::min(entry.first + entry.second->GetSize() - offset, entry.second->GetSize()); + if (length > read_in) { + return entry.second->Read(data, read_in, offset - entry.first) + + Read(data + read_in, length - read_in, offset + read_in); } - return entry->second->Read(data, length, offset - entry->first); + return entry.second->Read(data, std::min(read_in, length), offset - entry.first); } std::size_t ConcatenatedVfsFile::Write(const u8* data, std::size_t length, std::size_t offset) { @@ -93,4 +105,5 @@ std::size_t ConcatenatedVfsFile::Write(const u8* data, std::size_t length, std:: bool ConcatenatedVfsFile::Rename(std::string_view name) { return false; } + } // namespace FileSys |