owntone-server/src/daap-proto.c

/*
 * $Id$
 * Helper functions for formatting a daap message
 *
 * Copyright (C) 2003 Ron Pedde (ron@pedde.com)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include "daap-proto.h"
#include "err.h"
#include "restart.h"

/* Forwards */
DAAP_BLOCK *daap_get_new(void);
DAAP_BLOCK *daap_add_formatted(DAAP_BLOCK *parent, char *tag, 
			       int len, char *value);
/*
 * daap_get_new
 *
 * Initialize a new daap struct
 */
DAAP_BLOCK *daap_get_new(void) {
    DAAP_BLOCK *pnew;

    pnew=(DAAP_BLOCK*)malloc(sizeof(DAAP_BLOCK));
    if(!pnew) {
	DPRINTF(E_WARN,L_DAAP,"Error mallocing a daap block\n");
	return NULL;
    }

    pnew->free=0;
    pnew->value=NULL;
    pnew->parent=NULL;
    pnew->children=NULL;
    pnew->next=NULL;

    return pnew;
}

/*
 * daap_add_formatted
 *
 * add a block exactly as formatted in value.
 *
 * Note that value WILL be freed later in daap_free, so
 * the value paramater must have been malloced
 */
DAAP_BLOCK *daap_add_formatted(DAAP_BLOCK *parent, char *tag, 
			       int size, char *value) {
    DAAP_BLOCK *current,*last;
    DAAP_BLOCK *pnew;

    DPRINTF(E_DBG,L_DAAP,"Adding daap tag %s\n",tag);
    pnew = daap_get_new();
    if(!pnew)
	return NULL;

    pnew->reported_size=size;
    pnew->parent=parent;
    pnew->size=size;
    memcpy(pnew->tag,tag,4);

    if((size <= 4) && (size >= 0)) { /* we can just put it in svalue */
	memcpy(pnew->svalue,value,size);
	pnew->free=0;
    } else {
	pnew->value=value;
	pnew->free=1;
    }
    pnew->next=NULL;

    /* walk the child list and put it at the end */
    if(parent) {
	current=last=parent->children;
	while(current) {
	    last=current;
	    current=current->next;
	}
	
	if(last) { /* some there already */
	    last->next=pnew;
	} else {
	    parent->children=pnew;
	}
    }

    /* now, walk the chain and update sizes */
    current=pnew->parent;
    while(current) {
	current->reported_size += (8 + pnew->reported_size);
	current=current->parent;
    }

    return pnew;
}

/*
 * daap_add_int
 *
 * Add an int block to a specific parent
 */
DAAP_BLOCK *daap_add_long(DAAP_BLOCK *parent, char *tag, int v1, int v2) {
    char *ivalue;
    ivalue=(char*)malloc(8);
    if(!ivalue)
	return NULL;

    ivalue[0]=(v1 >> 24) & 0xFF;
    ivalue[1]=(v1 >> 16) & 0xFF;
    ivalue[2]=(v1 >> 8) & 0xFF;
    ivalue[3]=v1 & 0xFF;

    ivalue[4]=(v2 >> 24) & 0xFF;
    ivalue[5]=(v2 >> 16) & 0xFF;
    ivalue[6]=(v2 >> 8) & 0xFF;
    ivalue[7]=v2 & 0xFF;

    return daap_add_formatted(parent,tag,8,ivalue);
}

/*
 * daap_add_int
 *
 * Add an int block to a specific parent
 */
DAAP_BLOCK *daap_add_int(DAAP_BLOCK *parent, char *tag, int value) {
    char ivalue[4];

    ivalue[0]=(value >> 24) & 0xFF;
    ivalue[1]=(value >> 16) & 0xFF;
    ivalue[2]=(value >> 8) & 0xFF;
    ivalue[3]=value & 0xFF;

    return daap_add_formatted(parent,tag,4,ivalue);
}

/*
 * daap_add_short
 *
 * Add an int block to a specific parent
 */
DAAP_BLOCK *daap_add_short(DAAP_BLOCK *parent, char *tag, short int value) {
    char ivalue[2];

    ivalue[0]=(value >> 8) & 0xFF;
    ivalue[1]=value & 0xFF;

    return daap_add_formatted(parent,tag,2,ivalue);
}

/* 
 * daap_add_char
 *
 * Add a single char
 */
DAAP_BLOCK *daap_add_char(DAAP_BLOCK *parent, char *tag, char value) {
    return daap_add_formatted(parent,tag,1,&value);
}

/*
 * daap_add_data
 *
 * Add unstructured data to a specific parent
 */
DAAP_BLOCK *daap_add_data(DAAP_BLOCK *parent, char *tag, 
			  int len, void *value) {
    void *pvalue;

    if(len > 4) {
	pvalue=(void*)malloc(len);
	if(!pvalue)
	    return NULL;

	memcpy(pvalue,value,len);
    
	return daap_add_formatted(parent,tag,len,pvalue);
    } 
    return daap_add_formatted(parent,tag,len,value);
}

/*
 * daap_add_string
 *
 * Add a string element to a specific parent
 */
DAAP_BLOCK *daap_add_string(DAAP_BLOCK *parent, char *tag, char *value) {
    char *newvalue;

    if(value) {
	if(strlen(value) > 4) {
	    newvalue=strdup(value);
	    
	    if(!newvalue)
		return NULL;
	    
	    return daap_add_formatted(parent,tag,strlen(newvalue),newvalue);
	} 
	return daap_add_formatted(parent,tag,strlen(value),value);
    }
    return daap_add_formatted(parent,tag,0,"");
}

/*
 * daap_add_empty
 *
 * add a tag whose only value is to act as an aggregator
 */
DAAP_BLOCK *daap_add_empty(DAAP_BLOCK *parent, char *tag) {
    return daap_add_formatted(parent,tag,0,NULL);
}

/*
 * daap_serialmem
 *
 * Serialize a daap tree to a fd;
 */
int daap_serialize(DAAP_BLOCK *root, int fd, int gzip) {
    char size[4];

    while(root) {
	r_write(fd,root->tag,4);

	size[0] = (root->reported_size >> 24) & 0xFF;
	size[1] = (root->reported_size >> 16) & 0xFF;
	size[2] = (root->reported_size >> 8 ) & 0xFF;
	size[3] = (root->reported_size) & 0xFF;

	r_write(fd,&size,4);
	
	if(root->size) {
	    if(root->free)
		r_write(fd,root->value,root->size);
	    else
		r_write(fd,root->svalue,root->size);
	}
    
	if(root->children) {
	    if(daap_serialize(root->children,fd,gzip))
		return -1;
	}

	root=root->next;
    }
    
    return 0;
}

/*
 * daap_remove
 *
 * remove a node from it's parent node and release it
 */
void daap_remove(DAAP_BLOCK* node)
{
    DAAP_BLOCK*	parent = node->parent;

    if(0 != parent)
    {
	DAAP_BLOCK**	ptr = &parent->children;

	while(*ptr && *ptr != node)
	    ptr = &(**ptr).next;

	assert(0 != *ptr);
	
	// remove us from the chain
	*ptr = node->next;

	// update sizes in parent chain
	for(parent = node->parent ; parent ; parent = parent->parent)
	    parent->reported_size -= (8 + node->reported_size);
	
	// clear parent and next pointers so daap_free doesn't get ambitious
	node->parent = 0;
	node->next = 0;
    }
    
    daap_free(node);
}

/*
 * find a child block of the parent node
 */
DAAP_BLOCK *daap_find(DAAP_BLOCK *parent, char* tag)
{
    for(parent = parent->children ; parent ; parent = parent->next)
	if(!strncmp(parent->tag, tag, 4))
	    break;

    return parent;
}

/*
 * daap_free
 *
 * Free an entire daap formatted block
 */
void daap_free(DAAP_BLOCK *root) {
    DAAP_BLOCK *pnext;

    while(root) {
	DPRINTF(E_DBG,L_DAAP,"Freeing %c%c%c%c\n",root->tag[0],root->tag[1],
		root->tag[2],root->tag[3]);

	if((root->size) && (root->free))
	    free(root->value); /* otherwise, static value */

	daap_free(root->children);
	
	pnext=root->next;
	free(root);
	root=pnext;
    }
    return;
}

// search a block's children and change an integer value
int daap_set_int(DAAP_BLOCK* parent, char* tag, int value)
{
    DAAP_BLOCK*	child = daap_find(parent, tag);

    if(0 == child || child->size != sizeof(int))
	return 0;

    child->svalue[0]=(value >> 24) & 0xFF;
    child->svalue[1]=(value >> 16) & 0xFF;
    child->svalue[2]=(value >> 8) & 0xFF;
    child->svalue[3]=value & 0xFF;

    return 1;
}