e5e45ca1e3
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>
60 lines
1.7 KiB
Plaintext
60 lines
1.7 KiB
Plaintext
line_buffer API
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===============
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The line_buffer library provides a convenient interface for
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mostly-line-oriented input.
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Each line is not permitted to exceed 10000 bytes. The provided
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functions are not thread-safe or async-signal-safe, and like
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`fgets()`, they generally do not function correctly if interrupted
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by a signal without SA_RESTART set.
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Calling sequence
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----------------
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The calling program:
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- initializes a `struct line_buffer` to LINE_BUFFER_INIT
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- specifies a file to read with `buffer_init`
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- processes input with `buffer_read_line`, `buffer_read_string`,
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`buffer_skip_bytes`, and `buffer_copy_bytes`
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- closes the file with `buffer_deinit`, perhaps to start over and
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read another file.
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When finished, the caller can use `buffer_reset` to deallocate
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resources.
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Functions
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---------
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`buffer_init`::
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Open the named file for input. If filename is NULL,
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start reading from stdin. On failure, returns -1 (with
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errno indicating the nature of the failure).
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`buffer_deinit`::
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Stop reading from the current file (closing it unless
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it was stdin). Returns nonzero if `fclose` fails or
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the error indicator was set.
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`buffer_read_line`::
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Read a line and strip off the trailing newline.
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On failure or end of file, returns NULL.
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`buffer_read_string`::
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Read `len` characters of input or up to the end of the
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file, whichever comes first. Returns NULL on error.
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Returns whatever characters were read (possibly "")
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for end of file.
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`buffer_copy_bytes`::
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Read `len` bytes of input and dump them to the standard output
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stream. Returns early for error or end of file.
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`buffer_skip_bytes`::
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Discards `len` bytes from the input stream (stopping early
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if necessary because of an error or eof).
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`buffer_reset`::
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Deallocates non-static buffers.
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