MMFs + a scaled down hash set to use them with

2026-05-16 22:58:34 +00:00 · 2013-02-17 11:51:32 -08:00
parent 1c0f35a945
commit c734708809
4 changed files with 497 additions and 0 deletions
@@ -0,0 +1,193 @@
+#include "memory_mapped_file.h"
+#ifdef _WINDOWS
+#include <windows.h>
+#else
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <err.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+#endif
+#include "eqemu_exception.h"
+#include "ipc_mutex.h"
+
+namespace EQEmu {
+
+    struct MemoryMappedFile::Implementation {
+#ifdef _WINDOWS
+        HANDLE mapped_object_;
+#else
+        int fd_;
+#endif
+    };
+
+    MemoryMappedFile::MemoryMappedFile(std::string filename, uint32 size) 
+        : filename_(filename), size_(size) {
+        imp_ = new Implementation;
+        IPCMutex mut(filename + "Internal");
+    
+        if(!mut.Lock()) {
+            EQ_EXCEPT("Shared Memory", "Could not lock shared mutex.");
+        }
+    
+#ifdef _WINDOWS
+        DWORD total_size = size + sizeof(shared_memory_struct);
+        HANDLE file = CreateFile(filename.c_str(), 
+            GENERIC_READ | GENERIC_WRITE, 
+            FILE_SHARE_READ | FILE_SHARE_WRITE, 
+            NULL,
+            OPEN_ALWAYS,
+            0,
+            NULL);
+    
+        if(file == INVALID_HANDLE_VALUE) {
+            EQ_EXCEPT("Shared Memory", "Could not open a file for this shared memory segment.");
+        }
+    
+        imp_->mapped_object_ = CreateFileMapping(file,
+            NULL,
+            PAGE_READWRITE, 
+            0,
+            total_size,
+            filename.c_str());
+    
+        if(!imp_->mapped_object_) {
+            mut.Unlock();
+            EQ_EXCEPT("Shared Memory", "Could not create a file mapping for this shared memory file.");
+        }
+    
+        memory_ = reinterpret_cast<shared_memory_struct*>(MapViewOfFile(imp_->mapped_object_,
+            FILE_MAP_ALL_ACCESS,
+            0,
+            0, 
+            total_size));
+    
+        if(!memory_) {
+            mut.Unlock();
+            EQ_EXCEPT("Shared Memory", "Could not map a view of the shared memory file.");
+        }
+    
+#else
+        size_t total_size = size + sizeof(shared_memory_struct);
+        imp_->fd_ = open(filename.c_str(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+        if(imp_->fd_ == -1) {
+            mut.Unlock();
+            EQ_EXCEPT("Shared Memory", "Could not open a file for this shared memory segment.");
+        }
+
+        if(ftruncate(imp_->fd_, total_size) == -1) {
+            EQ_EXCEPT("Shared Memory", "Could not set file size for this shared memory segment.");
+        }
+
+        memory_ = reinterpret_cast<shared_memory_struct*>(
+            mmap(NULL, total_size, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, imp_->fd_, 0));
+
+        if(memory_ == MAP_FAILED) {
+            mut.Unlock();
+            EQ_EXCEPT("Shared Memory", "Could not create a file mapping for this shared memory file.");
+        }
+#endif
+        mut.Unlock();
+    }
+    
+    MemoryMappedFile::MemoryMappedFile(std::string filename) 
+        : filename_(filename) {
+        imp_ = new Implementation;
+        IPCMutex mut(filename + "Internal");
+
+        if(!mut.Lock()) {
+            EQ_EXCEPT("Shared Memory", "Could not lock shared mutex.");
+        }
+    
+        //get existing size
+        FILE *f = fopen(filename.c_str(), "rb");
+        if(!f) {
+            EQ_EXCEPT("Shared Memory", "Could not open the file to find the existing file size.");
+        }
+        fseek(f, 0U, SEEK_END);
+        uint32 size = static_cast<uint32>(ftell(f)) - sizeof(shared_memory_struct);
+        fclose(f);
+
+#ifdef _WINDOWS
+        DWORD total_size = size + sizeof(shared_memory_struct);
+        HANDLE file = CreateFile(filename.c_str(), 
+            GENERIC_READ | GENERIC_WRITE, 
+            FILE_SHARE_READ | FILE_SHARE_WRITE, 
+            NULL,
+            OPEN_ALWAYS,
+            0,
+            NULL);
+    
+        if(file == INVALID_HANDLE_VALUE) {
+            EQ_EXCEPT("Shared Memory", "Could not open a file for this shared memory segment.");
+        }
+    
+        imp_->mapped_object_ = CreateFileMapping(file,
+            NULL,
+            PAGE_READWRITE, 
+            0,
+            total_size,
+            filename.c_str());
+    
+        if(!imp_->mapped_object_) {
+            mut.Unlock();
+            EQ_EXCEPT("Shared Memory", "Could not create a file mapping for this shared memory file.");
+        }
+    
+        memory_ = reinterpret_cast<shared_memory_struct*>(MapViewOfFile(imp_->mapped_object_,
+            FILE_MAP_ALL_ACCESS,
+            0,
+            0, 
+            total_size));
+    
+        if(!memory_) {
+            mut.Unlock();
+            EQ_EXCEPT("Shared Memory", "Could not map a view of the shared memory file.");
+        }
+    
+#else
+        size_t total_size = size + sizeof(shared_memory_struct);
+        imp_->fd_ = open(filename.c_str(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+        if(imp_->fd_ == -1) {
+            mut.Unlock();
+            EQ_EXCEPT("Shared Memory", "Could not open a file for this shared memory segment.");
+        }
+
+        if(ftruncate(imp_->fd_, total_size) == -1) {
+            EQ_EXCEPT("Shared Memory", "Could not set file size for this shared memory segment.");
+        }
+
+        memory_ = reinterpret_cast<shared_memory_struct*>(
+            mmap(NULL, total_size, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, imp_->fd_, 0));
+
+        if(memory_ == MAP_FAILED) {
+            mut.Unlock();
+            EQ_EXCEPT("Shared Memory", "Could not create a file mapping for this shared memory file.");
+        }
+#endif
+        mut.Unlock();
+    }
+
+    MemoryMappedFile::~MemoryMappedFile() {
+#ifdef _WINDOWS
+        if(imp_->mapped_object_) {
+            CloseHandle(imp_->mapped_object_);
+        }
+#else
+        if(memory_) {
+            size_t total_size = size_ + sizeof(shared_memory_struct);
+            munmap(reinterpret_cast<void*>(memory_), total_size);
+            close(imp_->fd_);
+        }
+#endif
+        delete imp_;
+    }
+    
+    void MemoryMappedFile::ZeroFile() {
+        memset(reinterpret_cast<void*>(memory_), 0, sizeof(shared_memory_struct));
+        memory_->loaded = false;
+        memory_->size = size_;
+    }
+} // EQEmu