1 files changed, 125 insertions, 0 deletions
diff --git a/qpid/cpp/src/qpid/sys/posix/MemoryMappedFile.cpp b/qpid/cpp/src/qpid/sys/posix/MemoryMappedFile.cpp
new file mode 100644
index 0000000000..b4292aa4bc
--- /dev/null
+++ b/qpid/cpp/src/qpid/sys/posix/MemoryMappedFile.cpp
@@ -0,0 +1,125 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+#include "qpid/sys/MemoryMappedFile.h"
+#include "qpid/Exception.h"
+#include "qpid/Msg.h"
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+namespace qpid {
+namespace sys {
+namespace {
+const std::string PAGEFILE_PREFIX("pf_");
+const std::string PATH_SEPARATOR("/");
+const std::string ESCAPE("%");
+const std::string VALID("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-.");
+std::string getFileName(const std::string& name, const std::string& dir)
+{
+    std::stringstream filename;
+    if (dir.size())  filename << dir << PATH_SEPARATOR << PAGEFILE_PREFIX;
+    size_t start = 0;
+    while (true) {
+        size_t i = name.find_first_not_of(VALID, start);
+        if (i == std::string::npos) {
+            filename << name.substr(start);
+            return filename.str();
+        } else {
+            if (i > start) filename << name.substr(start, i-start);
+            filename << ESCAPE << (int) name.at(i);
+            start = i+1;
+        }
+    }
+
+}
+}
+
+class MemoryMappedFilePrivate
+{
+    friend class MemoryMappedFile;
+    std::string path;
+    int fd;
+    MemoryMappedFilePrivate() : fd(0) {}
+};
+MemoryMappedFile::MemoryMappedFile() : state(new MemoryMappedFilePrivate) {}
+MemoryMappedFile::~MemoryMappedFile() { delete state; }
+
+void MemoryMappedFile::open(const std::string& name, const std::string& directory)
+{
+    // Ensure directory exists
+    if ( ::mkdir(directory.c_str(), S_IRWXU | S_IRGRP | S_IXGRP )!=0 && errno!=EEXIST ) {
+        throw qpid::Exception(QPID_MSG("Failed to create memory mapped file directory " << directory << ": " << qpid::sys::strError(errno)));
+    }
+
+    state->path = getFileName(name, directory);
+
+    int flags = O_CREAT | O_TRUNC | O_RDWR;
+    int fd = ::open(state->path.c_str(), flags, S_IRUSR | S_IWUSR);
+    if (fd == -1) throw qpid::Exception(QPID_MSG("Failed to open memory mapped file " << state->path << ": " << qpid::sys::strError(errno) << " [flags=" << flags << "]"));
+    state->fd = fd;
+}
+
+void MemoryMappedFile::close()
+{
+    ::close(state->fd);
+    ::unlink(state->path.c_str());
+}
+
+size_t MemoryMappedFile::getPageSize()
+{
+    return ::sysconf(_SC_PAGE_SIZE);
+}
+
+char* MemoryMappedFile::map(size_t offset, size_t size)
+{
+    int protection = PROT_READ | PROT_WRITE;
+    char* region = (char*) ::mmap(0, size, protection, MAP_SHARED, state->fd, offset);
+    if (region == MAP_FAILED) {
+        throw qpid::Exception(QPID_MSG("Failed to map page into memory: " << qpid::sys::strError(errno)));
+    }
+    return region;
+
+}
+
+void MemoryMappedFile::unmap(char* region, size_t size)
+{
+    ::munmap(region, size);
+}
+
+void MemoryMappedFile::flush(char* region, size_t size)
+{
+    ::msync(region, size, MS_ASYNC);
+}
+
+void MemoryMappedFile::expand(size_t offset)
+{
+    if ((::lseek(state->fd, offset - 1, SEEK_SET) == -1) || (::write(state->fd, "", 1) == -1)) {
+        throw qpid::Exception(QPID_MSG("Failed to expand paged queue file: " << qpid::sys::strError(errno)));
+    }
+}
+
+bool MemoryMappedFile::isSupported()
+{
+    return true;
+}
+
+}} // namespace qpid::sys