1 #include "buffer_entry.h"
2 #include <stdio.h>
3 #include <assert.h>
4 #include <stdlib.h>
5 #include <string.h>
6
7 struct __buffer_entry_t
8 {
9 FILE *fd;
10 cmph_uint8 * buff;
11 cmph_uint32 capacity, // buffer entry capacity
12 nbytes, // buffer entry used bytes
13 pos; // current read position in buffer entry
14 cmph_uint8 eof; // flag to indicate end of file
15 };
16
buffer_entry_new(cmph_uint32 capacity)17 buffer_entry_t * buffer_entry_new(cmph_uint32 capacity)
18 {
19 buffer_entry_t *buff_entry = (buffer_entry_t *)malloc(sizeof(buffer_entry_t));
20 if (!buff_entry) return NULL;
21 buff_entry->fd = NULL;
22 buff_entry->buff = NULL;
23 buff_entry->capacity = capacity;
24 buff_entry->nbytes = capacity;
25 buff_entry->pos = capacity;
26 buff_entry->eof = 0;
27 return buff_entry;
28 }
29
buffer_entry_open(buffer_entry_t * buffer_entry,char * filename)30 void buffer_entry_open(buffer_entry_t * buffer_entry, char * filename)
31 {
32 buffer_entry->fd = fopen(filename, "rb");
33 }
34
buffer_entry_set_capacity(buffer_entry_t * buffer_entry,cmph_uint32 capacity)35 void buffer_entry_set_capacity(buffer_entry_t * buffer_entry, cmph_uint32 capacity)
36 {
37 buffer_entry->capacity = capacity;
38 }
39
40
buffer_entry_get_capacity(buffer_entry_t * buffer_entry)41 cmph_uint32 buffer_entry_get_capacity(buffer_entry_t * buffer_entry)
42 {
43 return buffer_entry->capacity;
44 }
45
buffer_entry_load(buffer_entry_t * buffer_entry)46 static void buffer_entry_load(buffer_entry_t * buffer_entry)
47 {
48 free(buffer_entry->buff);
49 buffer_entry->buff = (cmph_uint8 *)calloc((size_t)buffer_entry->capacity, sizeof(cmph_uint8));
50 buffer_entry->nbytes = (cmph_uint32)fread(buffer_entry->buff, (size_t)1, (size_t)buffer_entry->capacity, buffer_entry->fd);
51 if (buffer_entry->nbytes != buffer_entry->capacity) buffer_entry->eof = 1;
52 buffer_entry->pos = 0;
53 }
54
buffer_entry_read_key(buffer_entry_t * buffer_entry,cmph_uint32 * keylen)55 cmph_uint8 * buffer_entry_read_key(buffer_entry_t * buffer_entry, cmph_uint32 * keylen)
56 {
57 cmph_uint8 * buf = NULL;
58 cmph_uint32 lacked_bytes = sizeof(*keylen);
59 cmph_uint32 copied_bytes = 0;
60 if(buffer_entry->eof && (buffer_entry->pos == buffer_entry->nbytes)) // end
61 {
62 free(buf);
63 return NULL;
64 }
65 if((buffer_entry->pos + lacked_bytes) > buffer_entry->nbytes)
66 {
67 copied_bytes = buffer_entry->nbytes - buffer_entry->pos;
68 lacked_bytes = (buffer_entry->pos + lacked_bytes) - buffer_entry->nbytes;
69 if (copied_bytes != 0) memcpy(keylen, buffer_entry->buff + buffer_entry->pos, (size_t)copied_bytes);
70 buffer_entry_load(buffer_entry);
71 }
72 memcpy(keylen + copied_bytes, buffer_entry->buff + buffer_entry->pos, (size_t)lacked_bytes);
73 buffer_entry->pos += lacked_bytes;
74
75 lacked_bytes = *keylen;
76 copied_bytes = 0;
77 buf = (cmph_uint8 *)malloc(*keylen + sizeof(*keylen));
78 memcpy(buf, keylen, sizeof(*keylen));
79 if((buffer_entry->pos + lacked_bytes) > buffer_entry->nbytes) {
80 copied_bytes = buffer_entry->nbytes - buffer_entry->pos;
81 lacked_bytes = (buffer_entry->pos + lacked_bytes) - buffer_entry->nbytes;
82 if (copied_bytes != 0) {
83 memcpy(buf + sizeof(*keylen), buffer_entry->buff + buffer_entry->pos, (size_t)copied_bytes);
84 }
85 buffer_entry_load(buffer_entry);
86 }
87 memcpy(buf+sizeof(*keylen)+copied_bytes, buffer_entry->buff + buffer_entry->pos, (size_t)lacked_bytes);
88 buffer_entry->pos += lacked_bytes;
89 return buf;
90 }
91
buffer_entry_destroy(buffer_entry_t * buffer_entry)92 void buffer_entry_destroy(buffer_entry_t * buffer_entry)
93 {
94 fclose(buffer_entry->fd);
95 buffer_entry->fd = NULL;
96 free(buffer_entry->buff);
97 buffer_entry->buff = NULL;
98 buffer_entry->capacity = 0;
99 buffer_entry->nbytes = 0;
100 buffer_entry->pos = 0;
101 buffer_entry->eof = 0;
102 free(buffer_entry);
103 }
104