| #include "buffer_entry.h" |
| #include <stdio.h> |
| #include <assert.h> |
| #include <stdlib.h> |
| #include <string.h> |
|
|
| struct __buffer_entry_t |
| { |
| FILE *fd; |
| cmph_uint8 * buff; |
| cmph_uint32 capacity, |
| nbytes, |
| pos; |
| cmph_uint8 eof; |
| }; |
|
|
| buffer_entry_t * buffer_entry_new(cmph_uint32 capacity) |
| { |
| buffer_entry_t *buff_entry = (buffer_entry_t *)malloc(sizeof(buffer_entry_t)); |
| if (!buff_entry) return NULL; |
| buff_entry->fd = NULL; |
| buff_entry->buff = NULL; |
| buff_entry->capacity = capacity; |
| buff_entry->nbytes = capacity; |
| buff_entry->pos = capacity; |
| buff_entry->eof = 0; |
| return buff_entry; |
| } |
|
|
| void buffer_entry_open(buffer_entry_t * buffer_entry, char * filename) |
| { |
| buffer_entry->fd = fopen(filename, "rb"); |
| } |
|
|
| void buffer_entry_set_capacity(buffer_entry_t * buffer_entry, cmph_uint32 capacity) |
| { |
| buffer_entry->capacity = capacity; |
| } |
|
|
|
|
| cmph_uint32 buffer_entry_get_capacity(buffer_entry_t * buffer_entry) |
| { |
| return buffer_entry->capacity; |
| } |
|
|
| static void buffer_entry_load(buffer_entry_t * buffer_entry) |
| { |
| free(buffer_entry->buff); |
| buffer_entry->buff = (cmph_uint8 *)calloc((size_t)buffer_entry->capacity, sizeof(cmph_uint8)); |
| buffer_entry->nbytes = (cmph_uint32)fread(buffer_entry->buff, (size_t)1, (size_t)buffer_entry->capacity, buffer_entry->fd); |
| if (buffer_entry->nbytes != buffer_entry->capacity) buffer_entry->eof = 1; |
| buffer_entry->pos = 0; |
| } |
|
|
| cmph_uint8 * buffer_entry_read_key(buffer_entry_t * buffer_entry, cmph_uint32 * keylen) |
| { |
| cmph_uint8 * buf = NULL; |
| cmph_uint32 lacked_bytes = sizeof(*keylen); |
| cmph_uint32 copied_bytes = 0; |
| if(buffer_entry->eof && (buffer_entry->pos == buffer_entry->nbytes)) |
| { |
| free(buf); |
| return NULL; |
| } |
| if((buffer_entry->pos + lacked_bytes) > buffer_entry->nbytes) |
| { |
| copied_bytes = buffer_entry->nbytes - buffer_entry->pos; |
| lacked_bytes = (buffer_entry->pos + lacked_bytes) - buffer_entry->nbytes; |
| if (copied_bytes != 0) memcpy(keylen, buffer_entry->buff + buffer_entry->pos, (size_t)copied_bytes); |
| buffer_entry_load(buffer_entry); |
| } |
| memcpy(keylen + copied_bytes, buffer_entry->buff + buffer_entry->pos, (size_t)lacked_bytes); |
| buffer_entry->pos += lacked_bytes; |
|
|
| lacked_bytes = *keylen; |
| copied_bytes = 0; |
| buf = (cmph_uint8 *)malloc(*keylen + sizeof(*keylen)); |
| memcpy(buf, keylen, sizeof(*keylen)); |
| if((buffer_entry->pos + lacked_bytes) > buffer_entry->nbytes) { |
| copied_bytes = buffer_entry->nbytes - buffer_entry->pos; |
| lacked_bytes = (buffer_entry->pos + lacked_bytes) - buffer_entry->nbytes; |
| if (copied_bytes != 0) { |
| memcpy(buf + sizeof(*keylen), buffer_entry->buff + buffer_entry->pos, (size_t)copied_bytes); |
| } |
| buffer_entry_load(buffer_entry); |
| } |
| memcpy(buf+sizeof(*keylen)+copied_bytes, buffer_entry->buff + buffer_entry->pos, (size_t)lacked_bytes); |
| buffer_entry->pos += lacked_bytes; |
| return buf; |
| } |
|
|
| void buffer_entry_destroy(buffer_entry_t * buffer_entry) |
| { |
| fclose(buffer_entry->fd); |
| buffer_entry->fd = NULL; |
| free(buffer_entry->buff); |
| buffer_entry->buff = NULL; |
| buffer_entry->capacity = 0; |
| buffer_entry->nbytes = 0; |
| buffer_entry->pos = 0; |
| buffer_entry->eof = 0; |
| free(buffer_entry); |
| } |
|
|
