buffer_entry.c and buffer_entry.h added

src/buffer_entry.c

@@ -0,0 +1,86 @@
+#include "buffer_entry.h"
+#include <stdio.h>
+#include <assert.h>
+#include <stdlib.h>
+
+struct __buffer_entry_t
+{
+	FILE *fd;
+	cmph_uint8 * buff;
+	cmph_uint32 capacity, // buffer entry capacity
+		    nbytes,   // buffer entry used bytes
+		    pos;      // current read position in buffer entry
+	cmph_uint8  eof;      // flag to indicate end of file
+};
+
+buffer_entry_t * buffer_entry_new(cmph_uint32 capacity)
+{
+	buffer_entry_t *buff_entry = (buffer_entry_t *)malloc(sizeof(buffer_entry_t));
+	assert(buff_entry);
+	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;
+}
+
+void buffer_entry_load(buffer_entry_t * buffer_entry)
+{
+	free(buffer_entry->buff);
+	buffer_entry->buff = (cmph_uint8 *)calloc(buffer_entry->capacity, sizeof(cmph_uint8));
+	buffer_entry->nbytes = fread(buffer_entry->buff, 1, 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_uint8 * buf = (cmph_uint8 *)malloc(BUFSIZ);
+	cmph_uint32 buf_pos = 0;
+	cmph_uint8 c;
+	while(1)
+	{
+		if(buffer_entry->eof && (buffer_entry->pos == buffer_entry->nbytes)) // end
+		{
+			free(buf);
+			return NULL;
+		}
+		if(buffer_entry->pos == buffer_entry->nbytes) buffer_entry_load(buffer_entry);
+		c = buffer_entry->buff[(buffer_entry->pos)++];
+		buf[buf_pos++] = c;
+		if(c == '\0') break;
+		if(buf_pos % BUFSIZ == 0) buf = (cmph_uint8 *)realloc(buf, buf_pos + BUFSIZ);
+	}
+	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);
+}

src/buffer_entry.h

@@ -0,0 +1,14 @@
+#ifndef __CMPH_BUFFER_ENTRY_H__
+#define __CMPH_BUFFER_ENTRY_H__
+
+#include "cmph_types.h"
+#include <stdio.h>
+typedef struct __buffer_entry_t buffer_entry_t;
+
+buffer_entry_t * buffer_entry_new(cmph_uint32 capacity);
+void buffer_entry_set_capacity(buffer_entry_t * buffer_entry, cmph_uint32 capacity);
+cmph_uint32 buffer_entry_get_capacity(buffer_entry_t * buffer_entry);
+void buffer_entry_open(buffer_entry_t * buffer_entry, char * filename);
+cmph_uint8 * buffer_entry_read_key(buffer_entry_t * buffer_entry);
+void buffer_entry_destroy(buffer_entry_t * buffer_entry);
+#endif