Interactions with the disk and cache. More...

#include <assert.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include "db_structs.h"
#include "../../schema/include/record.h"

Include dependency graph for diskio.h:

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Go to the source code of this file.

Data Structures
struct	linked_overflow

struct	key_value

struct	node
	The basic structure stored in memory. More...

struct	cached_node
	A struct for holding cached nodes. More...

Macros
#define	ORDER 4

Typedefs
typedef unsigned long	Key
	A key to a record. More...

Functions
bool	is_leaf (struct node *node)
	Verifies if the node is a leaf.

struct node *	read_node (Page addr)
	Reads a node from disk at a given address. More...

int	write_node (struct node *node, Page addr)
	Writes a node to disk (or cache) at a given address. If an error occurs returns -1.

int	remove_node (Page addr)
	Removes a node from disk at a given address. If an error occurs returns -1.

Page	create_addr ()
	Creates an address for a new node. If an error occurs returns -1. More...

int	init_db ()
	initializes the database

struct node *	create_node ()

int	add_to_cache (struct node *node, Page addr)
	Adds a node to the beginning of the linked list that is cache. If the size of cache is greater than the max cache size, the last node of the list is removed. More...

struct node *	get_from_cache (Page addr)
	Get a node from the cache. This node will be a copy of the node in the cache. More...

int	remove_node_from_cache (struct cached_node *last_node)
	Removes a node from cache, erasing it permanently.

void	free_node (struct node *node)
	Free's a node.

Variables
struct yacdb	db
	The database.

Detailed Description

Interactions with the disk and cache.

Author: Jack Royer

Date: 2022-05-29

Typedef Documentation

◆ Key

Key

A key to a record.

This type is mainly used for auto-documentation, in order to better destinguish keys from addresses.

Function Documentation

◆ add_to_cache()

int add_to_cache	(	struct node *	node,
		Page	addr
	)

Adds a node to the beginning of the linked list that is cache. If the size of cache is greater than the max cache size, the last node of the list is removed.

◆ create_addr()

Page create_addr ( )

Creates an address for a new node. If an error occurs returns -1.

TODO: Cache optimization

Returns: the page number or -1 if an error occurred.

◆ get_from_cache()

struct node * get_from_cache ( Page addr )

Get a node from the cache. This node will be a copy of the node in the cache.

If no node is found or an error occurs, returns NULL.

Get a node from the cache. This node will be a copy of the node in the cache.

◆ read_node()

struct node * read_node ( Page addr )

Reads a node from disk at a given address.

Parameters

addr	The page number of the node

Returns: a pointer to the node.

Exceptions

Returns NULL if an error occurred

Data Structures

Macros

Typedefs

Functions

Variables