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path: root/vcs-svn/line_buffer.h
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2011-03-27vcs-svn: make buffer_read_binary API more convenientLibravatar Jonathan Nieder1-1/+1
buffer_read_binary is a thin wrapper around fread, but its signature is wrong: - fread can fill an arbitrary in-memory buffer. buffer_read_binary is limited to buffers whose size is representable by a 32-bit integer. - The result from fread is the number of bytes actually read. buffer_read_binary only reports the number of bytes read by incrementing sb->len by that amount and returns void. Fix both: let buffer_read_binary accept a size_t instead of uint32_t for the number of bytes to read and as a convenience return the number of bytes actually read. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-03-26vcs-svn: remove buffer_read_stringLibravatar Jonathan Nieder1-3/+1
All previous users of buffer_read_string have already been converted to use the more intuitive buffer_read_binary, so remove the old API to avoid some confusion. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-03-22vcs-svn: make buffer_copy_bytes return length readLibravatar Jonathan Nieder1-1/+2
Currently buffer_copy_bytes does not report to its caller whether it encountered an early end of file. Add a return value representing the number of bytes read (but not the number of bytes copied). This way all three unusual conditions can be distinguished: input error with buffer_ferror, output error with ferror(outfile), early end of input by checking the return value. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-03-22vcs-svn: make buffer_skip_bytes return length readLibravatar Jonathan Nieder1-1/+1
Currently there is no way to detect when input ended if it ended early during buffer_skip_bytes. Tell the calling program how many bytes were actually skipped for easier debugging. Existing callers will still ignore early EOF. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-03-22vcs-svn: improve support for reading large filesLibravatar Jonathan Nieder1-2/+2
Move from uint32_t to off_t as the fundamental unit of length used by the line_buffer library. Performance would get worse if anything but I think it's worth it for support of deltas that need to skip large pieces (> 4 GiB). Exception: buffer_read_string still takes a uint32_t, since it keeps its result in an in-core obj_pool. Callers still have to be updated to take advantage of this. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-03-07vcs-svn: allow input errors to be detected promptlyLibravatar Jonathan Nieder1-0/+1
The line_buffer library silently flags input errors until buffer_deinit time; unfortunately, by that point usually errno is invalid. Expose the error flag so callers can check for and report errors early for easy debugging. some_error_prone_operation(...); if (buffer_ferror(buf)) return error("input error: %s", strerror(errno)); Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-02-26vcs-svn: teach line_buffer about temporary filesLibravatar Jonathan Nieder1-1/+6
It can sometimes be useful to write information temporarily to file, to read back later. These functions allow a program to use the line_buffer facilities when doing so. It works like this: 1. find a unique filename with buffer_tmpfile_init. 2. rewind with buffer_tmpfile_rewind. This returns a stdio handle for writing. 3. when finished writing, declare so with buffer_tmpfile_prepare_to_read. The return value indicates how many bytes were written. 4. read whatever portion of the file is needed. 5. if finished, remove the temporary file with buffer_deinit. otherwise, go back to step 2, The svn support would use this to buffer the postimage from delta application until the length is known and fast-import can receive the resulting blob. Based-on-patch-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-02-26vcs-svn: allow input from file descriptorLibravatar Jonathan Nieder1-0/+1
Based-on-patch-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-02-26vcs-svn: allow character-oriented inputLibravatar Jonathan Nieder1-0/+1
buffer_read_char can be used in place of buffer_read_string(1) to avoid consuming valuable static buffer space. The delta applier will use this to read variable-length integers one byte at a time. Underneath, it is fgetc, wrapped so the line_buffer library can maintain its role as gatekeeper of input. Later it might be worth checking if fgetc_unlocked is faster --- most line_buffer functions are not thread-safe anyway. Helpd-by: David Barr <david.barr@cordelta.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-02-26vcs-svn: add binary-safe read functionLibravatar Jonathan Nieder1-0/+1
buffer_read_string works well for non line-oriented input except for one problem: it does not tell the caller how many bytes were actually written. This means that unless one is very careful about checking for errors (and eof) the calling program cannot tell the difference between the string "foo" followed by an early end of file and the string "foo\0bar\0baz". So introduce a variant that reports the length, too, a thinner wrapper around strbuf_fread. Its result is written to a strbuf so the caller does not need to keep track of the number of bytes read. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-02-26vcs-svn: teach line_buffer to handle multiple input filesLibravatar Jonathan Nieder1-7/+7
Collect the line_buffer state in a newly public line_buffer struct. Callers can use multiple line_buffers to manage input from multiple files at a time. svn-fe's delta applier will use this to stream a delta from svnrdump and the preimage it applies to from fast-import at the same time. The tests don't take advantage of the new features, but I think that's okay. It is easier to find lingering examples of nonreentrant code by searching for "static" in line_buffer.c. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2011-02-26vcs-svn: collect line_buffer data in a structLibravatar Jonathan Nieder1-0/+11
Prepare for the line_buffer lib to support input from multiple files, by collecting global state in a struct that can be easily passed around. No API change yet. Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2010-08-14Add stream helper libraryLibravatar David Barr1-0/+12
This library provides thread-unsafe fgets()- and fread()-like functions where the caller does not have to supply a buffer. It maintains a couple of static buffers and provides an API to use them. [rr: allow input from files other than stdin] [jn: with tests, documentation, and error handling improvements] Signed-off-by: David Barr <david.barr@cordelta.com> Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>