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+/* gzlog.h
+ Copyright (C) 2004 Mark Adler, all rights reserved
+ version 1.0, 26 Nov 2004
+
+ This software is provided 'as-is', without any express or implied
+ warranty. In no event will the author be held liable for any damages
+ arising from the use of this software.
+
+ Permission is granted to anyone to use this software for any purpose,
+ including commercial applications, and to alter it and redistribute it
+ freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+ 2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+ 3. This notice may not be removed or altered from any source distribution.
+
+ Mark Adler madler@alumni.caltech.edu
+ */
+
+/*
+ The gzlog object allows writing short messages to a gzipped log file,
+ opening the log file locked for small bursts, and then closing it. The log
+ object works by appending stored data to the gzip file until 1 MB has been
+ accumulated. At that time, the stored data is compressed, and replaces the
+ uncompressed data in the file. The log file is truncated to its new size at
+ that time. After closing, the log file is always valid gzip file that can
+ decompressed to recover what was written.
+
+ A gzip header "extra" field contains two file offsets for appending. The
+ first points to just after the last compressed data. The second points to
+ the last stored block in the deflate stream, which is empty. All of the
+ data between those pointers is uncompressed.
+ */
+
+/* Open a gzlog object, creating the log file if it does not exist. Return
+ NULL on error. Note that gzlog_open() could take a long time to return if
+ there is difficulty in locking the file. */
+void *gzlog_open(char *path);
+
+/* Write to a gzlog object. Return non-zero on error. This function will
+ simply write data to the file uncompressed. Compression of the data
+ will not occur until gzlog_close() is called. It is expected that
+ gzlog_write() is used for a short message, and then gzlog_close() is
+ called. If a large amount of data is to be written, then the application
+ should write no more than 1 MB at a time with gzlog_write() before
+ calling gzlog_close() and then gzlog_open() again. */
+int gzlog_write(void *log, char *data, size_t len);
+
+/* Close a gzlog object. Return non-zero on error. The log file is locked
+ until this function is called. This function will compress stored data
+ at the end of the gzip file if at least 1 MB has been accumulated. Note
+ that the file will not be a valid gzip file until this function completes.
+ */
+int gzlog_close(void *log);