Some callers may want to know whether convert_to_git will
actually do anything before performing the conversion
itself (e.g., to decide whether to stream or handle blobs
in-core). This patch lets callers specify the dry run mode
by passing a NULL destination buffer. The return value,
instead of indicating whether conversion happened, will
indicate whether conversion would occur.
For readability, we also include a wrapper function which
makes it more obvious we are not actually performing the
conversion.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some filters may need to buffer the input and look-ahead inside it
to decide what to output, and they may consume more than zero bytes
of input and still not produce any output. After feeding all the
input, pass NULL as input as keep calling stream_filter() to let
such filters know there is no more input coming, and it is time for
them to produce the remaining output based on the buffered input.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This introduces an API to plug custom filters to an input stream.
The caller gets get_stream_filter("path") to obtain an appropriate
filter for the path, and then uses it when opening an input stream
via open_istream(). After that, the caller can read from the stream
with read_istream(), and close it with close_istream(), just like an
unfiltered stream.
This only adds a "null" filter that is a pass-thru filter, but later
changes can add LF-to-CRLF and other filters, and the callers of the
streaming API do not have to change.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before adding the streaming filter API to the conversion layer,
move the existing declarations related to the conversion to its
own header file.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
