deflateCopy

z_rs

Function deflateCopy 

Source 
#[unsafe(export_name = "deflateCopy")]
pub unsafe extern "C-unwind" fn deflateCopy(
    dest: *mut z_stream,
    source: *mut z_stream,
) -> i32
Expand description

Sets the destination stream as a complete copy of the source stream.

This function can be useful when several compression strategies will be tried, for example when there are several ways of pre-processing the input data with a filter. The streams that will be discarded should then be freed by calling deflateEnd. Note that deflateCopy duplicates the internal compression state which can be quite large, so this strategy is slow and can consume lots of memory.

§Returns

  • Z_OK if success
  • Z_MEM_ERROR if there was not enough memory
  • Z_STREAM_ERROR if the source stream state was inconsistent (such as zalloc being NULL)

The msg field is left unchanged in both source and destination.

§Safety

The caller must guarantee that

  • Either
    • dest is NULL
    • dest satisfies the requirements of &mut *(dest as *mut MaybeUninit<z_stream>)
  • Either
    • source is NULL
    • source satisfies the requirements of &mut *strm and was initialized with deflateInit_ or similar