fish-shell/env_universal_common.h

#ifndef FISH_ENV_UNIVERSAL_COMMON_H
#define FISH_ENV_UNIVERSAL_COMMON_H

#include <wchar.h>
#include <queue>
#include <string>
#include "util.h"

/**
   The set command
*/
#define SET_STR L"SET"

/**
   The set_export command
*/
#define SET_EXPORT_STR L"SET_EXPORT"

/**
   The erase command
*/
#define ERASE_STR L"ERASE"

/**
   The barrier command
*/
#define BARRIER_STR L"BARRIER"

/**
   The barrier_reply command
*/
#define BARRIER_REPLY_STR L"BARRIER_REPLY"


/**
   The filename to use for univeral variables. The username is appended
*/
#define SOCK_FILENAME "fishd.socket."

/**
   The different types of commands that can be sent between client/server
*/
typedef enum
{
    SET,
    SET_EXPORT,
    ERASE,
    BARRIER,
    BARRIER_REPLY,
} fish_message_type_t;

/**
   The size of the buffer used for reading from the socket
*/
#define ENV_UNIVERSAL_BUFFER_SIZE 1024

/**
   A struct representing a message to be sent between client and server
*/
typedef struct
{
    /**
       Number of queues that contain this message. Once this reaches zero, the message should be deleted
    */
    int count;

    /**
       Message body. The message must be allocated using enough memory to actually contain the message.
    */
    std::string body;

} message_t;

typedef std::queue<message_t *> message_queue_t;

/**
   This struct represents a connection between a universal variable server/client
*/
typedef struct connection
{
    /**
       The file descriptor this socket lives on
    */
    int fd;
    /**
       Queue of onsent messages
    */
    message_queue_t *unsent;
    /**
       Set to one when this connection should be killed
    */
    int killme;
    /**
       The input string. Input from the socket goes here. When a
       newline is encountered, the buffer is parsed and cleared.
    */
    std::vector<char> input;

    /**
       The read buffer.
    */
    char buffer[ENV_UNIVERSAL_BUFFER_SIZE];

    /**
       Number of bytes that have already been consumed.
    */
    size_t buffer_consumed;

    /**
       Number of bytes that have been read into the buffer.
    */
    size_t buffer_used;


    /**
       Link to the next connection
    */
    struct connection *next;
}
connection_t;

/**
   Read all available messages on this connection
*/
void read_message(connection_t *);

/**
   Send as many messages as possible without blocking to the connection
*/
void try_send_all(connection_t *c);

/**
   Create a messge with the specified properties
*/
message_t *create_message(fish_message_type_t type, const wchar_t *key, const wchar_t *val);

/**
   Init the library
*/
void env_universal_common_init(void (*cb)(fish_message_type_t type, const wchar_t *key, const wchar_t *val));

/**
   Destroy library data
*/
void env_universal_common_destroy();

/**
   Add all variable names to the specified list

   This function operate agains the local copy of all universal
   variables, it does not communicate with any other process.
*/
void env_universal_common_get_names(wcstring_list_t &lst,
                                    int show_exported,
                                    int show_unexported);

/**
   Perform the specified variable assignment.

   This function operate agains the local copy of all universal
   variables, it does not communicate with any other process.

   Do not call this function. Create a message to do it. This function
   is only to be used when fishd is dead.
*/
void env_universal_common_set(const wchar_t *key, const wchar_t *val, int exportv);

/**
   Remove the specified variable.

   This function operate agains the local copy of all universal
   variables, it does not communicate with any other process.

   Do not call this function. Create a message to do it. This function
   is only to be used when fishd is dead.
*/
void env_universal_common_remove(const wcstring &key);

/**
   Get the value of the variable with the specified name

   This function operate agains the local copy of all universal
   variables, it does not communicate with any other process.
*/
wchar_t *env_universal_common_get(const wcstring &name);

/**
   Get the export flag of the variable with the specified
   name. Returns 0 if the variable doesn't exist.

   This function operate agains the local copy of all universal
   variables, it does not communicate with any other process.
*/
int env_universal_common_get_export(const wcstring &name);

/**
   Add messages about all existing variables to the specified connection
*/
void enqueue_all(connection_t *c);

/**
   Fill in the specified connection_t struct. Use the specified file
   descriptor for communication.
*/
void connection_init(connection_t *c, int fd);

/**
   Close and destroy the specified connection struct. This frees
   allstructures allocated by the connection, such as ques of unsent
   messages.
*/
void connection_destroy(connection_t *c);

#endif