mirror of https://github.com/yandex/odyssey.git
93 lines
2.0 KiB
C
93 lines
2.0 KiB
C
#ifndef ODYSSEY_READAHEAD_H
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#define ODYSSEY_READAHEAD_H
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/*
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* Odyssey.
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*
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* Scalable PostgreSQL connection pooler.
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*/
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typedef struct od_readahead od_readahead_t;
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struct od_readahead {
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machine_msg_t *buf;
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int size;
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int pos;
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int pos_read;
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};
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static inline void od_readahead_init(od_readahead_t *readahead)
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{
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readahead->buf = NULL;
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readahead->size = 0;
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readahead->pos = 0;
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readahead->pos_read = 0;
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}
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static inline void od_readahead_free(od_readahead_t *readahead)
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{
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if (readahead->buf)
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machine_msg_free(readahead->buf);
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}
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static inline int od_readahead_prepare(od_readahead_t *readahead, int size)
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{
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readahead->size = size;
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readahead->buf = machine_msg_create(size);
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if (readahead->buf == NULL)
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return -1;
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return 0;
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}
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static inline int od_readahead_left(od_readahead_t *readahead)
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{
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assert(readahead->buf);
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return readahead->size - readahead->pos;
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}
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static inline int od_readahead_unread(od_readahead_t *readahead)
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{
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return readahead->pos - readahead->pos_read;
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}
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static inline char *od_readahead_pos(od_readahead_t *readahead)
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{
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return (char *)machine_msg_data(readahead->buf) + readahead->pos;
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}
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static inline char *od_readahead_pos_read(od_readahead_t *readahead)
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{
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return (char *)machine_msg_data(readahead->buf) + readahead->pos_read;
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}
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static inline void od_readahead_pos_advance(od_readahead_t *readahead,
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int value)
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{
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readahead->pos += value;
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}
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static inline void od_readahead_pos_read_advance(od_readahead_t *readahead,
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int value)
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{
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readahead->pos_read += value;
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}
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static inline void od_readahead_reuse(od_readahead_t *readahead)
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{
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size_t unread = od_readahead_unread(readahead);
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if (unread > sizeof(sizeof(kiwi_header_t)))
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return;
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if (unread == 0) {
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readahead->pos = 0;
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readahead->pos_read = 0;
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return;
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}
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/* save next packet header */
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char *data = machine_msg_data(readahead->buf);
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memmove(data, data + readahead->pos_read, unread);
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readahead->pos = unread;
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readahead->pos_read = 0;
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}
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#endif /* ODYSSEY_READAHEAD_H */
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