内存映射写磁盘

Source_Files/ximeaimager.cpp

@@ -938,7 +938,28 @@ WriteData2Disk::WriteData2Disk()
 void WriteData2Disk::write2Disk()
 {
     QString imageFileName=m_QbaseFileName+".bil";
-    FILE *hFile=fopen(imageFileName.toStdString().c_str(),"w+b");
+//    FILE *hFile=fopen(imageFileName.toStdString().c_str(),"w+b");
+
+
+    int fd = open(imageFileName.toStdString().c_str(), O_RDWR | O_CREAT, S_IRUSR | S_IWUSR);
+
+    size_t fileSize = m_iFrameSizeInByte*(size_t)100*(size_t)60*(size_t)5;
+    size_t fileSizeIncrement = m_iFrameSizeInByte*(size_t)100*(size_t)60*(size_t)5;
+    if (lseek(fd, fileSize - 1, SEEK_SET) == -1) {
+        std::cerr << "Error calling lseek()\n";
+        return;
+    }
+    if (write(fd, "", 1) == -1) {
+        std::cerr << "Error writing last byte of the file\n";
+        return;
+    }
+    void* addr = mmap(nullptr, fileSize, PROT_WRITE, MAP_SHARED, fd, 0);
+    if (addr == MAP_FAILED) {
+        std::cerr << "Error mmapping the file\n";
+        return;
+    }
+
+    size_t sizeWrited2disk = 0;
 
     int frameCounter = 0;
     int frameNumber;
@@ -975,13 +996,71 @@ void WriteData2Disk::write2Disk()
 
 
 //        std::cout<<"WriteData2Disk::write2Disk-----------------------正在写磁盘!" << m_pool->max_size() <<std::endl;//
-        fwrite(dataBuffer,1,m_iFrameSizeInByte*frameNumber, hFile);
+
+
+        if (fileSize < sizeWrited2disk + m_iFrameSizeInByte*frameNumber)
+        {
+//            if (munmap(addr, fileSize) == -1) {
+//                std::cerr << "Error un-mmapping the file\n";
+//            }
+
+//            std::cout<<"老fileSize：" << fileSize <<std::endl;
+            size_t new_size = fileSize + fileSizeIncrement;
+            if (ftruncate(fd, new_size) == -1) {
+                std::cerr << "Error calling ftruncate()\n";
+                return;
+            }
+
+            // Remap the file with the new size
+            addr = mremap(addr, fileSize, new_size, MREMAP_MAYMOVE);
+            if (addr == MAP_FAILED) {
+                std::cerr << "Error calling mremap()\n";
+                return;
+            }
+
+            fileSize = new_size;
+//            std::cout<<"新fileSize：" << fileSize <<std::endl;
+
+        }
+//        fwrite(dataBuffer,1,m_iFrameSizeInByte*frameNumber, hFile);
+        memcpy(addr + sizeWrited2disk, dataBuffer, m_iFrameSizeInByte*frameNumber);
+
+        sizeWrited2disk = sizeWrited2disk + m_iFrameSizeInByte*frameNumber;
+//        std::cout<<"sizeWrited2disk：" << sizeWrited2disk <<std::endl;
+
         frameCounter++;
     }
     m_rgbImage->m_VideoWriter.release();
-    fclose(hFile);
+//    fclose(hFile);
     delete[] dataBuffer;
 
+
+
+
+//    if (munmap(addr, fileSize) == -1) {
+//        std::cerr << "Error un-mmapping the file\n";
+//    }
+
+    // Resize the file to 4096 bytes
+    if (ftruncate(fd, sizeWrited2disk) == -1) {
+        std::cerr << "Error calling ftruncate()\n";
+        return;
+    }
+
+    // Remap the file with the new size
+    addr = mremap(addr, fileSize, sizeWrited2disk, MREMAP_MAYMOVE);
+    if (addr == MAP_FAILED) {
+        std::cerr << "Error calling mremap()\n";
+        return;
+    }
+
+    if (munmap(addr, sizeWrited2disk) == -1) {
+        std::cerr << "Error un-mmapping the file\n";
+    }
+
+    close(fd);
+
+
     std::cout<<"WriteData2Disk::write2Disk-----------------------写磁盘线程将退出，内存池可达到的最多元素数：" << m_pool->max_size() <<std::endl;
     std::cout<<"WriteData2Disk::write2Disk-----------------------写磁盘线程将退出，fwrite 调用次数：" << frameCounter <<std::endl;
 }