EnumerateNamedStreams Event

Fires when the OS needs to enumerate a file's named streams.


virtual int FireEnumerateNamedStreams(CBFSEnumerateNamedStreamsEventParams *e);
typedef struct {
const char *FileName;
int NamedStreamFound;
char *StreamName; int lenStreamName;
int64 *pStreamSize;
int64 *pStreamAllocationSize;
int64 HandleInfo;
void *FileContext;
void *HandleContext;
void *EnumerationContext;
int ResultCode; int reserved; } CBFSEnumerateNamedStreamsEventParams;
virtual INT FireEnumerateNamedStreams(CBFSEnumerateNamedStreamsEventParams *e);
typedef struct {
BOOL NamedStreamFound;
LPWSTR StreamName; INT lenStreamName;
LONG64 *pStreamSize;
LONG64 *pStreamAllocationSize;
LONG64 HandleInfo;
LPVOID FileContext;
LPVOID HandleContext;
LPVOID EnumerationContext;
INT ResultCode; INT reserved; } CBFSEnumerateNamedStreamsEventParams;


This event fires when the OS needs to enumerate the named streams of the file specified by FileName (which will have been opened via OpenFile).

This event only needs to be handled if the UseAlternateDataStreams property is enabled. To handle this event properly, applications must return information about each of the file's named streams. For each named stream, set StreamNameFound to true and supply the named stream's information using the following parameters:

  • StreamName: Set to the name of the named stream.
    • The name must be copied to StreamName; set lenStreamName to the length of the copied string (measured in char/wchar_t, not including terminating nulls).
    • The length of the returned name must not exceed the value of the MaxFileNameLength property.
  • StreamSize: Set the size, in bytes, of the named stream's data.
  • StreamAllocationSize: Set to the number of bytes allocated locally for the named stream. This is typically a multiple of the ClusterSize.

If there are no more named streams present, set StreamNameFound to false and leave the above parameters unchanged. When the OS is finished with the named streams enumeration, the CloseNamedStreamsEnumeration event will fire.

The HandleInfo parameter carries a handle to an object with information about the file handle. While within the event handler, it can be used to call any of the following methods: GetHandleCreatorProcessId, GetHandleCreatorProcessName, GetHandleCreatorThreadId, or GetHandleCreatorToken.

The FileContext, HandleContext, and EnumerationContext parameters are placeholders for application-defined data associated with the file, specific handle, and enumeration; respectively. Please refer to the Contexts topic for more information.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource isn't available, security checks failed, etc.), set it to a non-zero value to report an appropriate error. Please refer to the Error Reporting and Handling topic for more information.

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CBFS Connect 2020 C++ Edition - Version 20.0 [Build 7545]