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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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#ifndef DRIZZLED_INTERNAL_IOCACHE_H
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#define DRIZZLED_INTERNAL_IOCACHE_H
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#include <drizzled/internal/my_sys.h>
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#ifndef MYSYS_IOCACHE_H
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#define MYSYS_IOCACHE_H
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#include <mysys/my_sys.h>
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#if defined(__cplusplus)
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struct st_io_cache;
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typedef int (*IO_CACHE_CALLBACK)(struct st_io_cache*);
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struct st_io_cache /* Used when cacheing files */
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typedef struct st_io_cache_share
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pthread_mutex_t mutex; /* To sync on reads into buffer. */
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pthread_cond_t cond; /* To wait for signals. */
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pthread_cond_t cond_writer; /* For a synchronized writer. */
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/* Offset in file corresponding to the first byte of buffer. */
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/* If a synchronized write cache is the source of the data. */
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struct st_io_cache *source_cache;
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unsigned char *buffer; /* The read buffer. */
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unsigned char *read_end; /* Behind last valid byte of buffer. */
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int running_threads; /* threads not in lock. */
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int total_threads; /* threads sharing the cache. */
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int error; /* Last error. */
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typedef struct st_io_cache /* Used when cacheing files */
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/* Offset in file corresponding to the first byte of unsigned char* buffer. */
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my_off_t pos_in_file;
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unsigned char **current_pos, **current_end;
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The lock is for append buffer used in SEQ_READ_APPEND cache
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need mutex copying from append buffer to read buffer.
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pthread_mutex_t append_buffer_lock;
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The following is used when several threads are reading the
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same file in parallel. They are synchronized on disk
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accesses reading the cached part of the file asynchronously.
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It should be set to NULL to disable the feature. Only
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READ_CACHE mode is supported.
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IO_CACHE_SHARE *share;
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A caller will use my_b_read() macro to read from the cache
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if the data is already in cache, it will be simply copied with
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memcpy() and internal variables will be accordinging updated with
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my_off_t aio_read_pos;
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my_aio_result aio_result;
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void close_cached_file();
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bool real_open_cached_file();
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int init_io_cache(int file, size_t cachesize,
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enum cache_type type, my_off_t seek_offset,
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bool use_async_io, myf cache_myflags);
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void init_functions();
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bool reinit_io_cache(enum cache_type type_arg,
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my_off_t seek_offset,
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void setup_io_cache();
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bool open_cached_file(const char *dir,
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const char *prefix, size_t cache_size,
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typedef struct st_io_cache IO_CACHE; /* Used when cacheing files */
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extern int _my_b_get(st_io_cache *info);
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extern int _my_b_async_read(st_io_cache *info,unsigned char *Buffer,size_t Count);
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extern int my_block_write(st_io_cache *info, const unsigned char *Buffer,
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extern int init_io_cache(IO_CACHE *info,File file,size_t cachesize,
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enum cache_type type,my_off_t seek_offset,
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bool use_async_io, myf cache_myflags);
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extern bool reinit_io_cache(IO_CACHE *info,enum cache_type type,
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my_off_t seek_offset,bool use_async_io,
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extern void setup_io_cache(IO_CACHE* info);
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extern void init_io_cache_share(IO_CACHE *read_cache, IO_CACHE_SHARE *cshare,
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IO_CACHE *write_cache, uint32_t num_threads);
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extern void remove_io_thread(IO_CACHE *info);
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extern int _my_b_get(IO_CACHE *info);
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extern int _my_b_async_read(IO_CACHE *info,unsigned char *Buffer,size_t Count);
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extern int my_block_write(IO_CACHE *info, const unsigned char *Buffer,
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size_t Count, my_off_t pos);
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extern int my_b_flush_io_cache(st_io_cache *info, int need_append_buffer_lock);
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extern int my_b_flush_io_cache(IO_CACHE *info, int need_append_buffer_lock);
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#define flush_io_cache(info) my_b_flush_io_cache((info),1)
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} /* namespace internal */
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} /* namespace drizzled */
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#endif /* DRIZZLED_INTERNAL_IOCACHE_H */
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extern int end_io_cache(IO_CACHE *info);
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extern bool open_cached_file(IO_CACHE *cache,const char *dir,
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const char *prefix, size_t cache_size,
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extern bool real_open_cached_file(IO_CACHE *cache);
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extern void close_cached_file(IO_CACHE *cache);
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#if defined(__cplusplus)
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#endif /* MYSYS_IOCACHE_H */