Struct ExternalInputStreamStructInterop

Struct ExternalInputStreamStructInterop#

Struct Documentation#

struct ExternalInputStreamStructInterop#

This structure contains information about externally provided functions for reading data from an input stream, and it is used to construct a stream-object to be used with libCZI. Note on lifetime: The function pointers must remain valid until the function ‘close_function’ is called. The lifetime may extend beyond calling the ‘libCZI_ReleaseInputStream’ function for the corresponding stream-object.

Public Members

std::uintptr_t opaque_handle1#

A user parameter which is passed to the callback function.

std::uintptr_t opaque_handle2#

A user parameter which is passed to the callback function.

std::int32_t (*read_function)(std::uintptr_t opaque_handle1, std::uintptr_t opaque_handle2, std::uint64_t offset, void *pv, std::uint64_t size, std::uint64_t *ptrBytesRead, ExternalStreamErrorInfoInterop *error_info)#

Function pointer used to read data from the stream. This function might be called from an arbitrary thread, and it may be called concurrently from multiple threads. A 0 as return value indicates successful operation. A non-zero value indicates a non-recoverable error. In case of an error, the error_info parameter must be filled with the error information.

Param opaque_handle1:

The value of the opaque_handle1 field of the ExternalInputStreamStructInterop.

Param opaque_handle2:

The value of the opaque_handle2 field of the ExternalInputStreamStructInterop.

Param offset:

The offset in the stream where to start reading from.

Param pv:

[out] Pointer to the buffer where the data is to be stored.

Param size:

The size of the buffer (and the number of bytes to be read from the stream).

Param ptrBytesRead:

[out] If non-null, the number of bytes that actually could be read is to be put here.

Param error_info:

[out] If non-null, in case of an error (i.e. return value <>0), this parameter may be used to report additional error information.

void (*close_function)(std::uintptr_t opaque_handle1, std::uintptr_t opaque_handle2)#

Function pointer used to close the stream. This function is called only once, and up until this function is called, the read_function pointer must remain valid and operational. No assumptions should be made about when this function is called, so the implementation must be prepared to handle this function being called at any time (but not concurrently with calls to the read_function).

Param opaque_handle1:

The value of the opaque_handle1 field of the ExternalInputStreamStructInterop.

Param opaque_handle2:

The value of the opaque_handle2 field of the ExternalInputStreamStructInterop.

Contents