//stream 文件流
namespace fastcgi;

class stream{
	ctor(stream){
		if(! ( stream && stream.read && stream.write && stream.flush) ){ 
			error("构造参数不是有效的流对象",2); 
		}
		this = stream;
	};
	writeRecord  = function (fcgiRecord) {
		var header = { 
			BYTE version = 1;
			BYTE type = fcgiRecord.type; 
			WORD requestId = ..raw.swap(fcgiRecord.requestId,"WORD");
			WORD contentLength;
			BYTE paddingLength;
			BYTE reserved;
		};
		
		var contentData,contentLength,paddingLength = fcgiRecord.contentData,fcgiRecord.contentLength;
		if( contentData ){
			if(!contentLength){
				if( contentData[["_struct"]]){
					contentLength = ..raw.sizeof(contentData);
				}
				else {
					contentLength = #contentData;
				}
			}
			header.contentLength = ..raw.swap(contentLength,"WORD");
			paddingLength = contentLength % 8 ;
			if(paddingLength) {
				paddingLength = 8 - paddingLength;
				header.paddingLength = paddingLength;
			}
		} 

		this.write(header);
		if(contentData){  
			if( type(contentData) == type.buffer ){
				this.writeBuffer(contentData,contentLength);
			}
			else this.write(contentData);
			
			if(paddingLength) this.writeBuffer( ..raw.buffer(paddingLength) );
		}
	};   
	readRecord = function(buffer){
		
		var fcgiRecord = { 
			BYTE version = 1;
			BYTE type;
			WORD requestId;
			WORD contentLength;
			BYTE paddingLength;
			BYTE reserved; 
		}; 
		if( ! this.read(fcgiRecord) ){
			return null/*exit*/;
		}
		if( fcgiRecord.version != /*FCGI_VERSION_*/1 ){
			return null,"Unknown fastcgi version v" + fcgiRecord.version;
		}
		 
		fcgiRecord.requestId = ..raw.swap(fcgiRecord.requestId,"WORD");
 		fcgiRecord.contentLength = ..raw.swap(fcgiRecord.contentLength,"WORD");
		 	
		if (fcgiRecord.contentLength > 0) { 
		
			if (fcgiRecord.type === 1/*_FCGI_BEGIN_REQUEST*/){
				var beginRequestData = {
					WORD role;
					BYTE flags;
					BYTE reserved[5]; 
				}
				if ( ! this.read(beginRequestData) ) {
					return;
				}
				beginRequestData.role = ..raw.swap(beginRequestData.role,"WORD");
				fcgiRecord.contentData = beginRequestData;
				
			}
			else{
				if(buffer){
					this.readBuffer(buffer,fcgiRecord.contentLength);
					fcgiRecord.contentData = buffer;
				}
				else {
					fcgiRecord.contentData = this.read(fcgiRecord.contentLength);
				} 
			}
		} 
				
		if ( fcgiRecord.paddingLength > 0 ) {
			this.read(fcgiRecord.paddingLength);
		} 
		return fcgiRecord; 
	};
}