3.5.4 Hashing incrementally
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Availability::- use_module(library(crypto)).(can be autoloaded)
Source[det]crypto_data_context(+Data, +Context0, -Context)
Context0 is an existing computation context, and Context is the new context after hashing Data in addition to the previously hashed data. Context0 may be produced by a prior invocation of either crypto_context_new/2 or crypto_data_context/3 itself.

This predicate allows a hash to be computed in chunks, which may be important while working with Metalink (RFC 5854), BitTorrent or similar technologies, or simply with big files.