envi/binary.h

#ifndef RTS_BINARY_H
#define RTS_BINARY_H
#include "../envi/envi.h"
#include "../math/vector.h"
#include <fstream>
#include <sys/stat.h>
namespace rts{
//This class contains a bunch of functions useful for multidimensional binary file access
template< typename T, unsigned int D = 3 >
class binary{
protected:
	std::fstream file;		//file stream used for reading and writing
	std::string name;		//file name
	unsigned int R[D];		//resolution
	unsigned int header;	//header size (in bytes)
	//basic initialization
	void init(){
		memset(R, 0, sizeof(unsigned int) * D);		//initialize the resolution to zero
		header = 0;									//initialize the header size to zero
	}
	//returns the file size
	//	reads the file size from disk and returns it (in bytes)
	unsigned int get_file_size(){
		struct stat results;
		if(stat(name.c_str(), &results) == 0)
			return results.st_size;
		else return 0;
	}
	//make sure that the specified file size matches the file size on disk
	//	returns true/false
	bool test_file_size(){
		unsigned int npts = 1;				//initialize the number of data points to 1
		for(unsigned int i = 0; i<D; i++)	//iterate over each dimension
			npts *= R[i];					//compute the total number of data points in the file
		unsigned int datasize = npts * sizeof(T);//multiply the sum by the size of the template parameter
		if(datasize + header == get_file_size()) return true;	//if the byte size matches the file size, we're golden
		else return false;					//otherwise return an error
	}
	//open the file specified in "name" for binary reading and writing
	bool open_file(std::string filename){
		//open the file as binary for reading and writing
		file.open(filename.c_str(), std::ios::in | std::ios::out | std::ios::binary);
		//if the file is successful
		if(file){
			name = filename;		//set the name
			if(test_file_size())	//test the file size
				return true;
		}
		
		return false;
	}
public:
	//open a file, given the file name, resolution (as a vector) and header size
	bool open(std::string filename, vec<unsigned int, D> r, unsigned int h = 0){
		for(unsigned int i = 0; i < D; i++)		//set the dimensions of the binary file object
			R[i] = r[i];
		header = h;				//save the header size
		if(!open_file(filename)) return false;	//open the binary file
		return test_file_size();
	}
	T * saveZ(unsigned int page){
		T * p;
		if (page<1||page>R[2]){                       //make sure the bank number is right
			cout<<"wrong page";
			getchar();
			return NULL;
		}
		p=(T *)malloc(R[0]*R[1]*sizeof(T));            //memory allocation
		if (p==NULL)
			cout<<"memory allocation failure";		
		file.seekg(R[1]*R[0]*(page-1)*sizeof(T),ios::beg);   //write into memory from the binary file
		file.read((char *)p,R[0]*R[1]*sizeof(T));
		return p;
	}
	T * saveXY(unsigned x, unsigned y){
		T * px;
		unsigned int i;
		if (x<1||x>R[0]||y<1||y>R[1]){                       //make sure the sample and line number is right
			cout<<"wrong page";
			getchar();
			return NULL;
		}
		px=(T *)malloc(R[2]*sizeof(T));                      //memory allocation
		if (px==NULL)
			cout<<"memory allocation failure";	
		x=x-1;
		y=y-1;
		file.seekg((x+y*R[0])*sizeof(T),ios::beg);           //point to the certain sample and line
		for (i=0;i<R[2];i++)
		{
			file.read((char *)(px+i), sizeof(T));
			file.seekg((R[1]*R[0]-1)*sizeof(T),ios::cur);    //go to the next band
		}
		return px;
	
	}
	/*bool open(std::string filename, unsigned int X, unsigned int h = 0){
		return open(filename, vec<unsigned int, 1>(X), h);
	}
	bool open(std::string filename, unsigned int X, unsigned int Y, unsigned int h = 0){
		return open(filename, vec<unsigned int, 2>(X, Y), h);
	}
	bool open(std::string filename, unsigned int X, unsigned int Y, unsigned int Z, unsigned int h = 0){
		return open(filename, vec<unsigned int, 3>(X, Y, Z), h);
	}*/
};
}
#endif