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Diffstat (limited to 'funtools/util/zlib-1.2.3/examples/gzlog.h')
-rw-r--r-- | funtools/util/zlib-1.2.3/examples/gzlog.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/funtools/util/zlib-1.2.3/examples/gzlog.h b/funtools/util/zlib-1.2.3/examples/gzlog.h new file mode 100644 index 0000000..a800bd5 --- /dev/null +++ b/funtools/util/zlib-1.2.3/examples/gzlog.h @@ -0,0 +1,58 @@ +/* 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); |