1 #include "buffer_manager.h"
2 #include "buffer_entry.h"
3 #include <stdio.h>
4 #include <assert.h>
5 #include <stdlib.h>
6 struct __buffer_manager_t
7 {
8 cmph_uint32 memory_avail; // memory available
9 buffer_entry_t ** buffer_entries; // buffer entries to be managed
10 cmph_uint32 nentries; // number of entries to be managed
11 cmph_uint32 *memory_avail_list; // memory available list
12 int pos_avail_list; // current position in memory available list
13 };
14
buffer_manager_new(cmph_uint32 memory_avail,cmph_uint32 nentries)15 buffer_manager_t * buffer_manager_new(cmph_uint32 memory_avail, cmph_uint32 nentries)
16 {
17 cmph_uint32 memory_avail_entry, i;
18 buffer_manager_t *buff_manager = (buffer_manager_t *)malloc(sizeof(buffer_manager_t));
19 if (!buff_manager) return NULL;
20 buff_manager->memory_avail = memory_avail;
21 buff_manager->buffer_entries = (buffer_entry_t **)calloc((size_t)nentries, sizeof(buffer_entry_t *));
22 buff_manager->memory_avail_list = (cmph_uint32 *)calloc((size_t)nentries, sizeof(cmph_uint32));
23 buff_manager->pos_avail_list = -1;
24 buff_manager->nentries = nentries;
25 memory_avail_entry = buff_manager->memory_avail/buff_manager->nentries + 1;
26 for(i = 0; i < buff_manager->nentries; i++)
27 {
28 buff_manager->buffer_entries[i] = buffer_entry_new(memory_avail_entry);
29 }
30 return buff_manager;
31 }
32
buffer_manager_open(buffer_manager_t * buffer_manager,cmph_uint32 index,char * filename)33 void buffer_manager_open(buffer_manager_t * buffer_manager, cmph_uint32 index, char * filename)
34 {
35 buffer_entry_open(buffer_manager->buffer_entries[index], filename);
36 }
37
buffer_manager_read_key(buffer_manager_t * buffer_manager,cmph_uint32 index,cmph_uint32 * keylen)38 cmph_uint8 * buffer_manager_read_key(buffer_manager_t * buffer_manager, cmph_uint32 index, cmph_uint32 * keylen)
39 {
40 cmph_uint8 * key = NULL;
41 if (buffer_manager->pos_avail_list >= 0 ) // recovering memory
42 {
43 cmph_uint32 new_capacity = buffer_entry_get_capacity(buffer_manager->buffer_entries[index]) + buffer_manager->memory_avail_list[(buffer_manager->pos_avail_list)--];
44 buffer_entry_set_capacity(buffer_manager->buffer_entries[index], new_capacity);
45 }
46 key = buffer_entry_read_key(buffer_manager->buffer_entries[index], keylen);
47 if (key == NULL) // storing memory to be recovered
48 {
49 buffer_manager->memory_avail_list[++(buffer_manager->pos_avail_list)] = buffer_entry_get_capacity(buffer_manager->buffer_entries[index]);
50 }
51 return key;
52 }
53
buffer_manager_destroy(buffer_manager_t * buffer_manager)54 void buffer_manager_destroy(buffer_manager_t * buffer_manager)
55 {
56 cmph_uint32 i;
57 for(i = 0; i < buffer_manager->nentries; i++)
58 {
59 buffer_entry_destroy(buffer_manager->buffer_entries[i]);
60 }
61 free(buffer_manager->memory_avail_list);
62 free(buffer_manager->buffer_entries);
63 free(buffer_manager);
64 }
65