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-rw-r--r--src/core/file_sys/vfs_concat.cpp39
-rw-r--r--src/core/file_sys/vfs_concat.h34
2 files changed, 59 insertions, 14 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
diff --git a/src/core/file_sys/vfs_concat.h b/src/core/file_sys/vfs_concat.h
index 717d04bdc..c65c20d15 100644
--- a/src/core/file_sys/vfs_concat.h
+++ b/src/core/file_sys/vfs_concat.h
@@ -4,22 +4,54 @@
#pragma once
+#include <map>
#include <memory>
#include <string_view>
#include <boost/container/flat_map.hpp>
#include "core/file_sys/vfs.h"
+#include "core/file_sys/vfs_static.h"
namespace FileSys {
+class ConcatenatedVfsFile;
+
// Wrapper function to allow for more efficient handling of files.size() == 0, 1 cases.
VirtualFile ConcatenateFiles(std::vector<VirtualFile> files, std::string name = "");
+// Convenience function that turns a map of offsets to files into a concatenated file, filling gaps
+// with template parameter.
+template <u8 filler_byte>
+VirtualFile ConcatenateFiles(std::map<u64, VirtualFile> files, std::string name = "") {
+ if (files.empty())
+ return nullptr;
+ if (files.size() == 1)
+ return files.begin()->second;
+
+ for (auto iter = files.begin(); iter != --files.end();) {
+ const auto old = iter++;
+ if (old->first + old->second->GetSize() != iter->first) {
+ files.emplace(old->first + old->second->GetSize(),
+ std::make_shared<StaticVfsFile<filler_byte>>(iter->first - old->first -
+ old->second->GetSize()));
+ }
+ }
+
+ if (files.begin()->first != 0)
+ files.emplace(0, std::make_shared<StaticVfsFile<filler_byte>>(files.begin()->first));
+
+ return std::shared_ptr<VfsFile>(new ConcatenatedVfsFile(std::move(files), std::move(name)));
+}
+
// Class that wraps multiple vfs files and concatenates them, making reads seamless. Currently
// read-only.
class ConcatenatedVfsFile : public VfsFile {
friend VirtualFile ConcatenateFiles(std::vector<VirtualFile> files, std::string name);
+ template <u8 filler_byte>
+ friend VirtualFile ConcatenateFiles(std::map<u64, VirtualFile> files, std::string name);
+
ConcatenatedVfsFile(std::vector<VirtualFile> files, std::string name);
+ ConcatenatedVfsFile(std::map<u64, VirtualFile> files, std::string name);
public:
~ConcatenatedVfsFile() override;
@@ -36,7 +68,7 @@ public:
private:
// Maps starting offset to file -- more efficient.
- boost::container::flat_map<u64, VirtualFile> files;
+ std::map<u64, VirtualFile> files;
std::string name;
};