public RC xOpen(string zName, VirtualFile pFile, OPEN flags, out OPEN pOutFlags)
{
pOutFlags = 0;
// If argument zPath is a NULL pointer, this function is required to open a temporary file. Use this buffer to store the file name in.
//var zTmpname = new StringBuilder(MAX_PATH + 1); // Buffer used to create temp filename
var rc = RC.OK;
var eType = (OPEN)((int)flags & 0xFFFFFF00); // Type of file to open
var isExclusive = (flags & OPEN.EXCLUSIVE) != 0;
var isDelete = (flags & OPEN.DELETEONCLOSE) != 0;
var isCreate = (flags & OPEN.CREATE) != 0;
var isReadonly = (flags & OPEN.READONLY) != 0;
var isReadWrite = (flags & OPEN.READWRITE) != 0;
var isOpenJournal = (isCreate && (eType == OPEN.MASTER_JOURNAL || eType == OPEN.MAIN_JOURNAL || eType == OPEN.WAL));
// Check the following statements are true:
// (a) Exactly one of the READWRITE and READONLY flags must be set, and
// (b) if CREATE is set, then READWRITE must also be set, and
// (c) if EXCLUSIVE is set, then CREATE must also be set.
// (d) if DELETEONCLOSE is set, then CREATE must also be set.
Debug.Assert((!isReadonly || !isReadWrite) && (isReadWrite || isReadonly));
Debug.Assert(!isCreate || isReadWrite);
Debug.Assert(!isExclusive || isCreate);
Debug.Assert(!isDelete || isCreate);
// The main DB, main journal, WAL file and master journal are never automatically deleted. Nor are they ever temporary files.
//Debug.Assert((!isDelete && !string.IsNullOrEmpty(zName)) || eType != OPEN.MAIN_DB);
Debug.Assert((!isDelete && !string.IsNullOrEmpty(zName)) || eType != OPEN.MAIN_JOURNAL);
Debug.Assert((!isDelete && !string.IsNullOrEmpty(zName)) || eType != OPEN.MASTER_JOURNAL);
Debug.Assert((!isDelete && !string.IsNullOrEmpty(zName)) || eType != OPEN.WAL);
// Assert that the upper layer has set one of the "file-type" flags.
Debug.Assert(eType == OPEN.MAIN_DB || eType == OPEN.TEMP_DB || eType == OPEN.MAIN_JOURNAL || eType == OPEN.TEMP_JOURNAL ||
eType == OPEN.SUBJOURNAL || eType == OPEN.MASTER_JOURNAL || eType == OPEN.TRANSIENT_DB || eType == OPEN.WAL);
pFile.S = null;
// If the second argument to this function is NULL, generate a temporary file name to use
if (string.IsNullOrEmpty(zName))
{
Debug.Assert(isDelete && !isOpenJournal);
zName = Path.GetRandomFileName();
}
// Convert the filename to the system encoding.
if (zName.StartsWith("/") && !zName.StartsWith("//"))
zName = zName.Substring(1);
var dwDesiredAccess = (isReadWrite ? FileAccess.Read | FileAccess.Write : FileAccess.Read);
// SQLITE_OPEN_EXCLUSIVE is used to make sure that a new file is created. SQLite doesn't use it to indicate "exclusive access" as it is usually understood.
FileMode dwCreationDisposition;
if (isExclusive)
// Creates a new file, only if it does not already exist. */ If the file exists, it fails.
dwCreationDisposition = FileMode.CreateNew;
else if (isCreate)
// Open existing file, or create if it doesn't exist
dwCreationDisposition = FileMode.OpenOrCreate;
else
// Opens a file, only if it exists.
dwCreationDisposition = FileMode.Open;
var dwShareMode = FileShare.Read | FileShare.Write;
#if !(SQLITE_SILVERLIGHT || WINDOWS_MOBILE)
FileOptions dwFlagsAndAttributes;
#endif
if (isDelete)
#if !(SQLITE_SILVERLIGHT || WINDOWS_MOBILE)
dwFlagsAndAttributes = FileOptions.DeleteOnClose;
#endif
else
#if !(SQLITE_SILVERLIGHT || WINDOWS_MOBILE)
dwFlagsAndAttributes = FileOptions.None;
#endif
// Reports from the internet are that performance is always better if FILE_FLAG_RANDOM_ACCESS is used.
FileStream fs = null;
if (Environment.OSVersion.Platform >= PlatformID.Win32NT)
{
// retry opening the file a few times; this is because of a racing condition between a delete and open call to the FS
var retries = 3;
while (fs == null && retries > 0)
try
{
retries--;
#if WINDOWS_PHONE || SQLITE_SILVERLIGHT
fs = new IsolatedStorageFileStream(zConverted, dwCreationDisposition, dwDesiredAccess, dwShareMode, IsolatedStorageFile.GetUserStoreForApplication());
#elif !(SQLITE_SILVERLIGHT || WINDOWS_MOBILE)
fs = new FileStream(zName, dwCreationDisposition, dwDesiredAccess, dwShareMode, 4096, dwFlagsAndAttributes);
#else
fs = new FileStream(zName, dwCreationDisposition, dwDesiredAccess, dwShareMode, 4096);
#endif
#if DEBUG
SysEx.OSTRACE("OPEN {0} ({1})", fs.GetHashCode(), fs.Name);
#endif
}
catch (Exception) { Thread.Sleep(100); }
}
SysEx.OSTRACE("OPEN {0} {1} 0x{2:x} {3}", pFile.GetHashCode(), zName, dwDesiredAccess, fs == null ? "failed" : "ok");
if (fs == null ||
#if !(SQLITE_SILVERLIGHT || WINDOWS_MOBILE)
fs.SafeFileHandle.IsInvalid
#else
!fs.CanRead
#endif
)
{
#if SQLITE_SILVERLIGHT
pFile.lastErrno = 1;
#else
pFile.LastErrno = (uint)Marshal.GetLastWin32Error();
#endif
VirtualFile.winLogError(RC.CANTOPEN, "winOpen", zName);
return (isReadWrite ? xOpen(zName, pFile, ((flags | OPEN.READONLY) & ~(OPEN.CREATE | OPEN.READWRITE)), out pOutFlags) : SysEx.SQLITE_CANTOPEN_BKPT());
}
pOutFlags = (isReadWrite ? OPEN.READWRITE : OPEN.READONLY);
pFile.Clear();
pFile.IsOpen = true;
pFile.S = fs;
pFile.LastErrno = 0;
pFile.Vfs = this;
pFile.Shm = null;
pFile.Path = zName;
pFile.SectorSize = (uint)getSectorSize(zName);
return rc;
}
private static int FILEHANDLEID(VirtualFile fd)
{
return fd.GetHashCode();
}