SERVER-7497 refactor and rationalize mongo/util/file.h; create file.cpp

Remove the FileInterface base class.  Move the code for non-trivial members
of the File class into a new mongo/util/file.cpp.  Make the behavior of
Windows and non-Windows versions of functions match.  Test the return status
of every OS API and report all errors in detail.

1 files changed, 24 insertions, 194 deletions

diff --git a/src/mongo/util/file.h b/src/mongo/util/file.h
index 6b3edb25696..074b5f4d87a 100644
--- a/src/mongo/util/file.h
+++ b/src/mongo/util/file.h
@@ -17,214 +17,44 @@
 
 #pragma once
 
-#if !defined(_WIN32)
-#include "errno.h"
-#include <sys/mman.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <sys/statvfs.h>
-#endif
-#include "text.h"
+#include <boost/cstdint.hpp>
+#include <string>
+
+#include "mongo/platform/basic.h"
+#include "mongo/platform/cstdint.h"
 
 namespace mongo {
 
-#ifndef __sunos__
     typedef uint64_t fileofs;
-#else
-    typedef boost::uint64_t fileofs;
-#endif
 
-    /* NOTE: not thread-safe. (at least the windows implementation isn't. */
+    // NOTE: not thread-safe. (at least the windows implementation isn't)
 
-    class FileInterface {
-    public:
-        void open(const char *fn) {}
-        void write(fileofs o, const char *data, unsigned len) {}
-        void read(fileofs o, char *data, unsigned len) {}
-        bool bad() {return false;}
-        bool is_open() {return false;}
-        fileofs len() { return 0; }
-        void fsync() { verify(false); }
-
-        // shrink file to size bytes. No-op if file already smaller.
-        void truncate(fileofs size);
+    class File {
 
-        /** @return  -1 if error or unavailable */
-        static boost::intmax_t freeSpace(const string &path) { verify(false); return -1; }
-    };
-
-#if defined(_WIN32)
-#include <io.h>
-
-    class File : public FileInterface {
-        HANDLE fd;
-        bool _bad;
-        string _name;
-        void err(BOOL b=false) { /* false = error happened */
-            if( !b && !_bad ) {
-                _bad = true;
-                log() << "File " << _name << "I/O error " << GetLastError() << endl;
-            }
-        }
     public:
-        File() {
-            fd = INVALID_HANDLE_VALUE;
-            _bad = true;
-        }
-        ~File() {
-            if( is_open() ) CloseHandle(fd);
-            fd = INVALID_HANDLE_VALUE;
-        }
-        void open(const char *filename, bool readOnly=false , bool direct=false) {
-            _name = filename;
-            fd = CreateFile(
-                     toNativeString(filename).c_str(),
-                     ( readOnly ? 0 : GENERIC_WRITE ) | GENERIC_READ, FILE_SHARE_WRITE|FILE_SHARE_READ,
-                     NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
-            if( !is_open() ) {
-                DWORD e = GetLastError();
-                log() << "Create/Open File failed " << filename << ' ' << errnoWithDescription(e) << endl;
-            }
-            else
-                _bad = false;
-        }
-        static boost::intmax_t freeSpace(const string &path) {
-            ULARGE_INTEGER avail;
-            if( GetDiskFreeSpaceEx(toNativeString(path.c_str()).c_str(), &avail, NULL, NULL) ) { 
-                return avail.QuadPart;
-            }
-            DWORD e = GetLastError();
-            log() << "GetDiskFreeSpaceEx fails errno: " << e << endl;
-            return -1;
-        }
-        void write(fileofs o, const char *data, unsigned len) {
-            LARGE_INTEGER li;
-            li.QuadPart = o;
-            SetFilePointerEx(fd, li, NULL, FILE_BEGIN);
-            DWORD written;
-            err( WriteFile(fd, data, len, &written, NULL) );
-        }
-        void read(fileofs o, char *data, unsigned len) {
-            DWORD read;
-            LARGE_INTEGER li;
-            li.QuadPart = o;
-            SetFilePointerEx(fd, li, NULL, FILE_BEGIN);
-            int ok = ReadFile(fd, data, len, &read, 0);
-            if( !ok )
-                err(ok);
-            else
-                massert( 10438 , "ReadFile error - truncated file?", read == len);
-        }
-        bool bad() { return _bad; }
-        bool is_open() { return fd != INVALID_HANDLE_VALUE; }
-        fileofs len() {
-            LARGE_INTEGER li;
-            li.LowPart = GetFileSize(fd, (DWORD *) &li.HighPart);
-            if( li.HighPart == 0 && li.LowPart == INVALID_FILE_SIZE ) {
-                err( false );
-                return 0;
-            }
-            return li.QuadPart;
-        }
-        void fsync() { FlushFileBuffers(fd); }
-
-        void truncate(fileofs size) {
-            if (len() <= size)
-                return;
-
-            LARGE_INTEGER li;
-            li.QuadPart = size;
-            if (SetFilePointerEx(fd, li, NULL, FILE_BEGIN) == 0){
-                err(false);
-                return; //couldn't seek
-            }
-
-            err(SetEndOfFile(fd));
-        }
-    };
+        File();
+        ~File();
+
+        bool bad() const { return _bad; }
+        void fsync() const;
+        bool is_open() const;
+        fileofs len();
+        void open(const char* filename, bool readOnly = false, bool direct = false);
+        void read(fileofs o, char* data, unsigned len);
+        void truncate(fileofs size);
+        void write(fileofs o, const char* data, unsigned len);
 
-#else
+        static boost::intmax_t freeSpace(const std::string& path);
 
-    class File : public FileInterface {
-    public:
-        int fd;
     private:
         bool _bad;
-        void err(bool ok) {
-            if( !ok && !_bad ) {
-                _bad = true;
-                log() << "File I/O " << errnoWithDescription() << endl;
-            }
-        }
-    public:
-        File() {
-            fd = -1;
-            _bad = true;
-        }
-        ~File() {
-            if( is_open() ) ::close(fd);
-            fd = -1;
-        }
-
-#ifndef O_NOATIME
-#define O_NOATIME 0
-#endif
-
-        void open(const char *filename, bool readOnly=false , bool direct=false) {
-            fd = ::open(filename,
-                        O_CREAT | ( readOnly ? 0 : ( O_RDWR | O_NOATIME ) ) 
-#if defined(O_DIRECT)
-                        | ( direct ? O_DIRECT : 0 ) 
+#ifdef _WIN32
+        HANDLE _handle;
+#else
+        int _fd;
 #endif
-                        ,
-                        S_IRUSR | S_IWUSR);
-            if ( fd <= 0 ) {
-                out() << "couldn't open " << filename << ' ' << errnoWithDescription() << endl;
-                return;
-            }
-            _bad = false;
-        }
-        void write(fileofs o, const char *data, unsigned len) {
-            err( ::pwrite(fd, data, len, o) == (int) len );
-        }
-        void read(fileofs o, char *data, unsigned len) {
-            ssize_t s = ::pread(fd, data, len, o);
-            if( s == -1 ) {
-                err(false);
-            }
-            else if( s != (int) len ) { 
-                _bad = true;
-                log() << "File error read:" << s << " bytes, wanted:" << len << " ofs:" << o << endl;
-            }
-        }
-        bool bad() { return _bad; }
-        bool is_open() { return fd > 0; }
-        fileofs len() {
-            off_t o = lseek(fd, 0, SEEK_END);
-            if( o != (off_t) -1 )
-                return o;
-            err(false);
-            return 0;
-        }
-        void fsync() { ::fsync(fd); }
-        static boost::intmax_t freeSpace ( const string &path ) {
-            struct statvfs info;
-            verify( !statvfs( path.c_str() , &info ) );
-            return boost::intmax_t( info.f_bavail ) * info.f_frsize;
-        }
-
-        void truncate(fileofs size) {
-            if (len() <= size)
-                return;
+        std::string _name;
 
-            err(ftruncate(fd, size) == 0);
-        }
     };
 
-
-#endif
-
-
 }
-