mirror of https://github.com/schoebel/mars
136 lines
3.2 KiB
C
136 lines
3.2 KiB
C
// (c) 2010 Thomas Schoebel-Theuer / 1&1 Internet AG
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/* Definitions for logfile format.
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*
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* This is meant for sharing between different transaction logger variants,
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* and/or for sharing with userspace tools (e.g. logfile analyzers).
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* TODO: factor out some remaining kernelspace issues.
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*/
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#ifndef LIB_LOG_H
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#define LIB_LOG_H
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#include "mars.h"
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/* The following structure is memory-only.
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* Transfers to disk are indirectly via the
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* format conversion functions below.
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* The advantage is that even newer disk formats can be parsed
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* by old code (of course, not all information / features will be
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* available then).
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*/
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#define log_header log_header_v1
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struct log_header_v1 {
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struct timespec l_stamp;
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struct timespec l_written;
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loff_t l_pos;
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int l_len;
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int l_extra_len;
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short l_code;
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short l_extra;
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int l_crc; // NYI
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};
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#define FORMAT_VERSION 1 // version of disk format, currently there is no other one
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#define CODE_UNKNOWN 0
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#define CODE_WRITE_NEW 1
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#define CODE_WRITE_OLD 2
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#define START_MAGIC 0xa8f7e908d9177957ll
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#define END_MAGIC 0x74941fb74ab5726dll
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#define START_OVERHEAD \
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( \
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sizeof(START_MAGIC) + \
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sizeof(char) + \
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sizeof(char) + \
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sizeof(short) + \
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sizeof(struct timespec) + \
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sizeof(loff_t) + \
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sizeof(int) + \
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sizeof(int) + \
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sizeof(short) + \
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sizeof(short) + \
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0 \
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)
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#define END_OVERHEAD \
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( \
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sizeof(END_MAGIC) + \
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sizeof(int) + \
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sizeof(char) + \
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3 + 4 /*spare*/ + \
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sizeof(struct timespec) + \
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0 \
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)
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#define OVERHEAD (START_OVERHEAD + END_OVERHEAD)
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// TODO: make this bytesex-aware.
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#define DATA_PUT(data,offset,val) \
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do { \
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*((typeof(val)*)((data)+offset)) = val; \
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offset += sizeof(val); \
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} while (0)
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#define DATA_GET(data,offset,val) \
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do { \
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val = *((typeof(val)*)((data)+offset)); \
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offset += sizeof(val); \
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} while (0)
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////////////////////////////////////////////////////////////////////////////
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#ifdef __KERNEL__
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/* Bookkeeping status between calls
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*/
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struct log_status {
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// tunables
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int align_size; // alignment between requests
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int chunk_size; // must be at least 8K (better 64k)
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int io_prio;
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// informational
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int count;
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loff_t log_pos;
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// internal
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struct mars_input *input;
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struct mars_output *output;
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struct generic_object_layout ref_object_layout;
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struct mars_info info;
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int offset;
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int validflag_offset;
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int reallen_offset;
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int payload_offset;
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int payload_len;
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struct mref_object *log_mref;
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struct mref_object *read_mref;
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wait_queue_head_t event;
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int error_code;
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bool got;
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bool do_free;
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void *private;
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};
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void init_logst(struct log_status *logst, struct mars_input *input, struct mars_output *output, loff_t start_pos);
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void log_flush(struct log_status *logst);
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void *log_reserve(struct log_status *logst, struct log_header *lh);
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bool log_finalize(struct log_status *logst, int len, void (*preio)(void *private), void (*endio)(void *private, int error), void *private);
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int log_read(struct log_status *logst, struct log_header *lh, void **payload, int *payload_len);
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/////////////////////////////////////////////////////////////////////////
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// init
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extern int init_log_format(void);
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extern void exit_log_format(void);
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#endif
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#endif
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