65 lines
2.4 KiB
C
65 lines
2.4 KiB
C
#include "buffer_manager.h"
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#include "buffer_entry.h"
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#include <stdio.h>
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#include <assert.h>
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#include <stdlib.h>
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struct __buffer_manager_t
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{
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cmph_uint32 memory_avail; // memory available
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buffer_entry_t ** buffer_entries; // buffer entries to be managed
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cmph_uint32 nentries; // number of entries to be managed
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cmph_uint32 *memory_avail_list; // memory available list
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int pos_avail_list; // current position in memory available list
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};
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buffer_manager_t * buffer_manager_new(cmph_uint32 memory_avail, cmph_uint32 nentries)
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{
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cmph_uint32 memory_avail_entry, i;
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buffer_manager_t *buff_manager = (buffer_manager_t *)malloc(sizeof(buffer_manager_t));
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assert(buff_manager);
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buff_manager->memory_avail = memory_avail;
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buff_manager->buffer_entries = (buffer_entry_t **)calloc(nentries, sizeof(buffer_entry_t *));
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buff_manager->memory_avail_list = (cmph_uint32 *)calloc(nentries, sizeof(cmph_uint32));
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buff_manager->pos_avail_list = -1;
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buff_manager->nentries = nentries;
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memory_avail_entry = buff_manager->memory_avail/buff_manager->nentries + 1;
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for(i = 0; i < buff_manager->nentries; i++)
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{
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buff_manager->buffer_entries[i] = buffer_entry_new(memory_avail_entry);
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}
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return buff_manager;
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}
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void buffer_manager_open(buffer_manager_t * buffer_manager, cmph_uint32 index, char * filename)
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{
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buffer_entry_open(buffer_manager->buffer_entries[index], filename);
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}
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cmph_uint8 * buffer_manager_read_key(buffer_manager_t * buffer_manager, cmph_uint32 index, cmph_uint32 * keylen)
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{
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cmph_uint8 * key = NULL;
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if (buffer_manager->pos_avail_list >= 0 ) // recovering memory
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{
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cmph_uint32 new_capacity = buffer_entry_get_capacity(buffer_manager->buffer_entries[index]) + buffer_manager->memory_avail_list[(buffer_manager->pos_avail_list)--];
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buffer_entry_set_capacity(buffer_manager->buffer_entries[index], new_capacity);
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}
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key = buffer_entry_read_key(buffer_manager->buffer_entries[index], keylen);
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if (key == NULL) // storing memory to be recovered
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{
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buffer_manager->memory_avail_list[++(buffer_manager->pos_avail_list)] = buffer_entry_get_capacity(buffer_manager->buffer_entries[index]);
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}
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return key;
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}
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void buffer_manager_destroy(buffer_manager_t * buffer_manager)
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{
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cmph_uint32 i;
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for(i = 0; i < buffer_manager->nentries; i++)
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{
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buffer_entry_destroy(buffer_manager->buffer_entries[i]);
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}
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free(buffer_manager->memory_avail_list);
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free(buffer_manager->buffer_entries);
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free(buffer_manager);
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}
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