bdberl/c_src/bdberl_drv.c

/* -------------------------------------------------------------------
 *
 * bdberl: Berkeley DB Driver for Erlang
 * Copyright (c) 2008 The Hive.  All rights reserved.
 *
 * ------------------------------------------------------------------- */

#include <assert.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include "erl_driver.h"

#include "db.h"

/**
 * Driver functions
 */
static ErlDrvData bdberl_drv_start(ErlDrvPort port, char* buffer);

static void bdberl_drv_stop(ErlDrvData handle);

static int bdberl_drv_control(ErlDrvData handle, unsigned int cmd, 
                              char* inbuf, int inbuf_sz, 
                              char** outbuf, int outbuf_sz);

static void bdberl_ready_async(ErlDrvData handle, ErlDrvThreadData thread_data);

/**
 * Command codes
 */
#define CMD_OPEN_DB          0
#define CMD_CLOSE_DB         1
#define CMD_GET              2
#define CMD_PUT              3

/** 
 * Driver Entry
 */
ErlDrvEntry bdberl_drv_entry = 
{
    NULL,			/* F_PTR init, N/A */
    bdberl_drv_start,		/* L_PTR start, called when port is opened */
    bdberl_drv_stop,		/* F_PTR stop, called when port is closed */
    NULL,			/* F_PTR output, called when erlang has sent */
    NULL,			/* F_PTR ready_input, called when input descriptor ready */
    NULL,			/* F_PTR ready_output, called when output descriptor ready */
    "bdberl_drv",               /* driver_name */
    NULL,			/* F_PTR finish, called when unloaded */
    NULL,			/* handle */
    bdberl_drv_control,		/* F_PTR control, port_command callback */
    NULL,			/* F_PTR timeout, reserved */
    NULL,                       /* F_PTR outputv, reserved */
    bdberl_ready_async,         /* F_PTR ready_async */
    NULL,                       /* F_PTR flush */
    NULL,                       /* F_PTR call */
    NULL,                       /* F_PTR event */
    ERL_DRV_EXTENDED_MARKER,        
    ERL_DRV_EXTENDED_MAJOR_VERSION, 
    ERL_DRV_EXTENDED_MINOR_VERSION,
    ERL_DRV_FLAG_USE_PORT_LOCKING,
    NULL,                        /* Reserved */
    NULL                         /* F_PTR process_exit */
};

/**
 * Structure for holding port instance data
 */
typedef struct 
{
    ErlDrvPort port;
} PortData;

DRIVER_INIT(bdberl_drv) 
{
    return &bdberl_drv_entry;
}

static ErlDrvData bdberl_drv_start(ErlDrvPort port, char* buffer)
{
    PortData* d = (PortData*)driver_alloc(sizeof(PortData));
    memset(d, '\0', sizeof(PortData));

    // Save handle to the port
    d->port = port;

    // Make sure port is running in binary mode
    set_port_control_flags(port, PORT_CONTROL_FLAG_BINARY);

    return (ErlDrvData)d;
}

static void bdberl_drv_stop(ErlDrvData handle)
{
    // Release the port instance data
    driver_free(handle);
}

static int bdberl_drv_control(ErlDrvData handle, unsigned int cmd, 
                              char* inbuf, int inbuf_sz, 
                              char** outbuf, int outbuf_sz)
{
    //PortData* d = (PortData*)handle;
    DB* dbp;
    db_create(&dbp, NULL, 0);

    switch(cmd)
    {
    }
    *outbuf = 0;
    return 0;
}

static void bdberl_ready_async(ErlDrvData handle, ErlDrvThreadData thread_data)
{
}