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-rw-r--r--src/core/file_sys/vfs_concat.cpp38
1 files changed, 27 insertions, 11 deletions
diff --git a/src/core/file_sys/vfs_concat.cpp b/src/core/file_sys/vfs_concat.cpp
index dc7a279a9..d9f9911da 100644
--- a/src/core/file_sys/vfs_concat.cpp
+++ b/src/core/file_sys/vfs_concat.cpp
@@ -5,10 +5,23 @@
#include <algorithm>
#include <utility>
+#include "common/assert.h"
#include "core/file_sys/vfs_concat.h"
namespace FileSys {
+static bool VerifyConcatenationMapContinuity(const std::map<u64, VirtualFile>& map) {
+ const auto last_valid = --map.end();
+ for (auto iter = map.begin(); iter != last_valid;) {
+ 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;
@@ -27,6 +40,11 @@ ConcatenatedVfsFile::ConcatenatedVfsFile(std::vector<VirtualFile> files_, std::s
}
}
+ConcatenatedVfsFile::ConcatenatedVfsFile(std::map<u64, VirtualFile> files_, std::string name)
+ : files(std::move(files_)), name(std::move(name)) {
+ ASSERT(VerifyConcatenationMapContinuity(files));
+}
+
ConcatenatedVfsFile::~ConcatenatedVfsFile() = default;
std::string ConcatenatedVfsFile::GetName() const {
@@ -62,7 +80,7 @@ bool ConcatenatedVfsFile::IsReadable() const {
}
std::size_t ConcatenatedVfsFile::Read(u8* data, std::size_t length, std::size_t offset) const {
- auto entry = files.end();
+ auto entry = --files.end();
for (auto iter = files.begin(); iter != files.end(); ++iter) {
if (iter->first > offset) {
entry = --iter;
@@ -70,20 +88,17 @@ std::size_t ConcatenatedVfsFile::Read(u8* data, std::size_t length, std::size_t
}
}
- // 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<u64>(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<u64>(read_in, length), offset - entry->first);
}
std::size_t ConcatenatedVfsFile::Write(const u8* data, std::size_t length, std::size_t offset) {
@@ -93,4 +108,5 @@ std::size_t ConcatenatedVfsFile::Write(const u8* data, std::size_t length, std::
bool ConcatenatedVfsFile::Rename(std::string_view name) {
return false;
}
+
} // namespace FileSys