Jonathan Nieder 9d2f5ddfe5 vcs-svn: learn to maintain a sliding view of a file ... Each section of a Subversion-format delta only requires examining (and keeping in random-access memory) a small portion of the preimage. At any moment, this portion starts at a certain file offset and has a well-defined length, and as the delta is applied, the portion advances from the beginning to the end of the preimage. Add a move_window function to keep track of this view into the preimage. You can use it like this: buffer_init(f, NULL); struct sliding_view window = SLIDING_VIEW_INIT(f); move_window(&window, 3, 7); /* (1) */ move_window(&window, 5, 5); /* (2) */ move_window(&window, 12, 2); /* (3) */ strbuf_release(&window.buf); buffer_deinit(f); The data structure is called sliding_view instead of _window to prevent confusion with svndiff0 Windows. In this example, (1) reads 10 bytes and discards the first 3; (2) discards the first 2, which are not needed any more; and (3) skips 2 bytes and reads 2 new bytes to work with. When move_window returns, the file position indicator is at position window->off + window->width and the data from positions window->off to the current file position are stored in window->buf. This function performs only sequential access from the input file and never seeks, so it can be safely used on pipes and sockets. On end-of-file, move_window silently reads less than the caller requested. On other errors, it prints a message and returns -1. Helped-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>		2011-03-27 20:23:32 -05:00
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fast_export.c	vcs-svn: add missing cast to printf argument	2011-03-27 12:21:12 -05:00
fast_export.h	vcs-svn: handle log message with embedded NUL	2011-03-26 00:49:37 -05:00
LICENSE	vcs-svn: learn to maintain a sliding view of a file	2011-03-27 20:23:32 -05:00
line_buffer.c
line_buffer.h
line_buffer.txt
obj_pool.h
repo_tree.c	vcs-svn: handle log message with embedded NUL	2011-03-26 00:49:37 -05:00
repo_tree.h	vcs-svn: handle log message with embedded NUL	2011-03-26 00:49:37 -05:00
sliding_window.c	vcs-svn: learn to maintain a sliding view of a file	2011-03-27 20:23:32 -05:00
sliding_window.h	vcs-svn: learn to maintain a sliding view of a file	2011-03-27 20:23:32 -05:00
string_pool.c
string_pool.h
string_pool.txt
svndump.c	vcs-svn: handle log message with embedded NUL	2011-03-26 00:49:37 -05:00
svndump.h
trp.h
trp.txt