| Current File : //usr/include/libmemcachedprotocol-0.0/callback.h |
/*
* Summary: Definition of the callback interface
*
* Copy: See Copyright for the status of this software.
*
* Author: Trond Norbye
*/
#pragma once
/**
* Callback to send data back from a successful GET/GETQ/GETK/GETKQ command
*
* @param cookie Just pass along the cookie supplied in the callback
* @param key What to insert as key in the reply
* @param keylen The length of the key
* @param body What to store in the body of the package
* @param bodylen The number of bytes of the body
* @param flags The flags stored with the item
* @param cas The CAS value to insert into the response (should be 0
* if you don't care)
*/
typedef protocol_binary_response_status
(*memcached_binary_protocol_get_response_handler)(const void *cookie,
const void *key,
uint16_t keylen,
const void *body,
uint32_t bodylen,
uint32_t flags,
uint64_t cas);
/**
* Callback to send data back from a STAT command
*
* @param cookie Just pass along the cookie supplied in the callback
* @param key What to insert as key in the reply
* @param keylen The length of the key
* @param body What to store in the body of the package
* @param bodylen The number of bytes of the body
*/
typedef protocol_binary_response_status
(*memcached_binary_protocol_stat_response_handler)(const void *cookie,
const void *key,
uint16_t keylen,
const void *body,
uint32_t bodylen);
/**
* Callback to send data back from a VERSION command
*
* @param cookie Just pass along the cookie supplied in the callback
* @param text The version string
* @param length The number of bytes in the version string
*/
typedef protocol_binary_response_status
(*memcached_binary_protocol_version_response_handler)(const void *cookie,
const void *text,
uint32_t length);
/**
* In the low level interface you need to format the response
* packet yourself (giving you complete freedom :-)
*
* @param cookie Just pass along the cookie supplied in the callback
* @param request Pointer to the request packet you are sending a reply to
* @param response Pointer to the response packet to send
*
*/
typedef protocol_binary_response_status (*memcached_binary_protocol_raw_response_handler)(const void *cookie,
protocol_binary_request_header *request,
protocol_binary_response_header *response);
/**
* In the low lever interface you have to do most of the work by
* yourself, but it also gives you a lot of freedom :-)
* @param cookie identification for this connection, just pass it along to
* the response handler
* @param header the command received over the wire. Never try to access
* <u>anything</u> outside the command.
* @param resonse_handler call this function to send data back to the client
*/
typedef protocol_binary_response_status (*memcached_binary_protocol_command_handler)(const void *cookie,
protocol_binary_request_header *header,
memcached_binary_protocol_raw_response_handler response_handler);
/**
* The raw interface to the packets is implemented in version 0. It contains
* just an array with command handlers. The inxed in the array is the
* com code.
*/
typedef struct {
memcached_binary_protocol_command_handler comcode[256];
} memcached_binary_protocol_callback_v0_st;
/**
* The first version of the callback struct containing all of the
* documented commands in the initial release of the binary protocol
* (aka. memcached 1.4.0).
*
* You might miss the Q commands (addq etc) but the response function
* knows how to deal with them so you don't need to worry about that :-)
*/
typedef struct {
/**
* Add an item to the cache
* @param cookie id of the client receiving the command
* @param key the key to add
* @param len the length of the key
* @param val the value to store for the key (may be NIL)
* @param vallen the length of the data
* @param flags the flags to store with the key
* @param exptime the expiry time for the key-value pair
* @param cas the resulting cas for the add operation (if success)
*/
protocol_binary_response_status (*add)(const void *cookie,
const void *key,
uint16_t keylen,
const void* val,
uint32_t vallen,
uint32_t flags,
uint32_t exptime,
uint64_t *cas);
/**
* Append data to an <b>existing</b> key-value pair.
*
* @param cookie id of the client receiving the command
* @param key the key to add data to
* @param len the length of the key
* @param val the value to append to the value
* @param vallen the length of the data
* @param cas the CAS in the request
* @param result_cas the resulting cas for the append operation
*
*/
protocol_binary_response_status (*append)(const void *cookie,
const void *key,
uint16_t keylen,
const void* val,
uint32_t vallen,
uint64_t cas,
uint64_t *result_cas);
/**
* Decrement the value for a key
*
* @param cookie id of the client receiving the command
* @param key the key to decrement the value for
* @param len the length of the key
* @param delta the amount to decrement
* @param initial initial value to store (if the key doesn't exist)
* @param expiration expiration time for the object (if the key doesn't exist)
* @param cas the CAS in the request
* @param result the result from the decrement
* @param result_cas the cas of the item
*
*/
protocol_binary_response_status (*decrement)(const void *cookie,
const void *key,
uint16_t keylen,
uint64_t delta,
uint64_t initial,
uint32_t expiration,
uint64_t *result,
uint64_t *result_cas);
/**
* Delete an existing key
*
* @param cookie id of the client receiving the command
* @param key the key to delete_object
* @param len the length of the key
* @param cas the CAS in the request
*/
protocol_binary_response_status (*delete_object)(const void *cookie,
const void *key,
uint16_t keylen,
uint64_t cas);
/**
* Flush the cache
*
* @param cookie id of the client receiving the command
* @param when when the cache should be flushed (0 == immediately)
*/
protocol_binary_response_status (*flush_object)(const void *cookie,
uint32_t when);
/**
* Get a key-value pair
*
* @param cookie id of the client receiving the command
* @param key the key to get
* @param len the length of the key
* @param response_handler to send the result back to the client
*/
protocol_binary_response_status (*get)(const void *cookie,
const void *key,
uint16_t keylen,
memcached_binary_protocol_get_response_handler response_handler);
/**
* Increment the value for a key
*
* @param cookie id of the client receiving the command
* @param key the key to increment the value on
* @param len the length of the key
* @param delta the amount to increment
* @param initial initial value to store (if the key doesn't exist)
* @param expiration expiration time for the object (if the key doesn't exist)
* @param cas the CAS in the request
* @param result the result from the decrement
* @param result_cas the cas of the item
*
*/
protocol_binary_response_status (*increment)(const void *cookie,
const void *key,
uint16_t keylen,
uint64_t delta,
uint64_t initial,
uint32_t expiration,
uint64_t *result,
uint64_t *result_cas);
/**
* The noop command was received. This is just a notification callback (the
* response is automatically created).
*
* @param cookie id of the client receiving the command
*/
protocol_binary_response_status (*noop)(const void *cookie);
/**
* Prepend data to an <b>existing</b> key-value pair.
*
* @param cookie id of the client receiving the command
* @param key the key to prepend data to
* @param len the length of the key
* @param val the value to prepend to the value
* @param vallen the length of the data
* @param cas the CAS in the request
* @param result-cas the cas id of the item
*
*/
protocol_binary_response_status (*prepend)(const void *cookie,
const void *key,
uint16_t keylen,
const void* val,
uint32_t vallen,
uint64_t cas,
uint64_t *result_cas);
/**
* The quit command was received. This is just a notification callback (the
* response is automatically created).
*
* @param cookie id of the client receiving the command
*/
protocol_binary_response_status (*quit)(const void *cookie);
/**
* Replace an <b>existing</b> item to the cache
*
* @param cookie id of the client receiving the command
* @param key the key to replace the content for
* @param len the length of the key
* @param val the value to store for the key (may be NIL)
* @param vallen the length of the data
* @param flags the flags to store with the key
* @param exptime the expiry time for the key-value pair
* @param cas the cas id in the request
* @param result_cas the cas id of the item
*/
protocol_binary_response_status (*replace)(const void *cookie,
const void *key,
uint16_t keylen,
const void* val,
uint32_t vallen,
uint32_t flags,
uint32_t exptime,
uint64_t cas,
uint64_t *result_cas);
/**
* Set a key-value pair in the cache
*
* @param cookie id of the client receiving the command
* @param key the key to insert
* @param len the length of the key
* @param val the value to store for the key (may be NIL)
* @param vallen the length of the data
* @param flags the flags to store with the key
* @param exptime the expiry time for the key-value pair
* @param cas the cas id in the request
* @param result_cas the cas id of the new item
*/
protocol_binary_response_status (*set)(const void *cookie,
const void *key,
uint16_t keylen,
const void* val,
uint32_t vallen,
uint32_t flags,
uint32_t exptime,
uint64_t cas,
uint64_t *result_cas);
/**
* Get status information
*
* @param cookie id of the client receiving the command
* @param key the key to get status for (or NIL to request all status).
* Remember to insert the terminating packet if multiple
* packets should be returned.
* @param keylen the length of the key
* @param response_handler to send the result back to the client, but
* don't send reply on success!
*
*/
protocol_binary_response_status (*stat)(const void *cookie,
const void *key,
uint16_t keylen,
memcached_binary_protocol_stat_response_handler response_handler);
/**
* Get the version information
*
* @param cookie id of the client receiving the command
* @param response_handler to send the result back to the client, but
* don't send reply on success!
*
*/
protocol_binary_response_status (*version)(const void *cookie,
memcached_binary_protocol_version_response_handler response_handler);
} memcached_binary_protocol_callback_v1_st;
/**
* The version numbers for the different callback structures.
*/
typedef enum {
/** Version 0 is a lowlevel interface that tries to maximize your freedom */
MEMCACHED_PROTOCOL_HANDLER_V0= 0,
/**
* Version 1 abstracts more of the protocol details, and let you work at
* a logical level
*/
MEMCACHED_PROTOCOL_HANDLER_V1= 1
} memcached_protocol_interface_version_t;
/**
* Definition of the protocol callback structure.
*/
typedef struct {
/**
* The interface version you provide callbacks for.
*/
memcached_protocol_interface_version_t interface_version;
/**
* Callback fired just before the command will be executed.
*
* @param cookie id of the client receiving the command
* @param header the command header as received on the wire. If you look
* at the content you <b>must</b> ensure that you don't
* try to access beyond the end of the message.
*/
void (*pre_execute)(const void *cookie,
protocol_binary_request_header *header);
/**
* Callback fired just after the command was exected (please note
* that the data transfer back to the client is not finished at this
* time).
*
* @param cookie id of the client receiving the command
* @param header the command header as received on the wire. If you look
* at the content you <b>must</b> ensure that you don't
* try to access beyond the end of the message.
*/
void (*post_execute)(const void *cookie,
protocol_binary_request_header *header);
/**
* Callback fired if no specialized callback is registered for this
* specific command code.
*
* @param cookie id of the client receiving the command
* @param header the command header as received on the wire. You <b>must</b>
* ensure that you don't try to access beyond the end of the
* message.
* @param response_handler The response handler to send data back.
*/
protocol_binary_response_status (*unknown)(const void *cookie,
protocol_binary_request_header *header,
memcached_binary_protocol_raw_response_handler response_handler);
/**
* The different interface levels we support. A pointer is used so the
* size of the structure is fixed. You must ensure that the memory area
* passed as the pointer is valid as long as you use the protocol handler.
*/
union {
memcached_binary_protocol_callback_v0_st v0;
/**
* The first version of the callback struct containing all of the
* documented commands in the initial release of the binary protocol
* (aka. memcached 1.4.0).
*/
memcached_binary_protocol_callback_v1_st v1;
} interface;
} memcached_binary_protocol_callback_st;