|
private leveldb_free ( |
||
| ptr | ||
| return | void | |
protected override bool ReleaseHandle()
{
if (handle != default(IntPtr))
{
LevelDbInterop.leveldb_free(handle);
}
handle = default(IntPtr);
return(true);
}
static void Throw(IntPtr error, Func <string, Exception> exception)
{
if (error != IntPtr.Zero)
{
try {
var msg = Marshal.PtrToStringAnsi(error);
throw exception(msg);
} finally {
LevelDbInterop.leveldb_free(error);
}
}
}
/// <summary>
/// DB implementations can export properties about their state
/// via this method. If "property" is a valid property understood by this
/// DB implementation, fills "*value" with its current value and returns
/// true. Otherwise returns false.
///
/// Valid property names include:
///
/// "leveldb.num-files-at-level<N>" - return the number of files at level <N>,
/// where <N> is an ASCII representation of a level number (e.g. "0").
/// "leveldb.stats" - returns a multi-line string that describes statistics
/// about the internal operation of the DB.
/// </summary>
public string PropertyValue(string name)
{
var ptr = LevelDbInterop.leveldb_property_value(Handle, name);
if (ptr == IntPtr.Zero)
{
return(null);
}
try {
return(Marshal.PtrToStringAnsi(ptr));
} finally {
LevelDbInterop.leveldb_free(ptr);
}
}
/// <summary>
/// If the database contains an entry for "key" return the value,
/// otherwise return null.
/// </summary>
public byte[] Get(byte[] key, ReadOptions options)
{
IntPtr error;
IntPtr length;
var v = LevelDbInterop.leveldb_get(Handle, options.Handle, key, (IntPtr)key.LongLength, out length, out error);
Throw(error);
if (v == IntPtr.Zero)
{
return(null);
}
try {
var bytes = new byte[(long)length];
// TODO: Consider copy loop, as Marshal.Copy has 2GB-1 limit, or native pointers
Marshal.Copy(v, bytes, 0, (int)length);
return(bytes);
} finally {
LevelDbInterop.leveldb_free(v);
}
}
/// <summary>
/// If the database contains an entry for "key" return the value,
/// otherwise return null.
/// </summary>
public int[] Get(int key, ReadOptions options)
{
IntPtr error;
IntPtr length;
IntPtr v;
v = LevelDbInterop.leveldb_get(Handle, options.Handle, ref key, (IntPtr)sizeof(int), out length, out error);
Throw(error);
if (v == IntPtr.Zero)
{
return(null);
}
try {
var bytes = new int[(long)length / 4];
// TODO: consider >2GB-1
Marshal.Copy(v, bytes, 0, checked ((int)bytes.LongLength));
return(bytes);
} finally {
LevelDbInterop.leveldb_free(v);
}
}
