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