a portable and fast pairing-based cryptography library
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mcl/include/cybozu/stream.hpp

267 lines
6.6 KiB

#pragma once
/**
@file
@brief stream and line stream class
@author MITSUNARI Shigeo(@herumi)
*/
#ifndef CYBOZU_DONT_USE_STRING
#include <string>
#include <iosfwd>
#endif
#include <cybozu/exception.hpp>
#include <memory.h>
namespace cybozu {
namespace stream_local {
template <typename From, typename To>
struct is_convertible {
typedef char yes;
typedef int no;
static no test(...);
static yes test(const To*);
static const bool value = sizeof(test(static_cast<const From*>(0))) == sizeof(yes);
};
template <bool b, class T = void>
struct enable_if { typedef T type; };
template <class T>
struct enable_if<false, T> {};
#ifndef CYBOZU_DONT_USE_STRING
/* specialization for istream */
template<class InputStream>
size_t readSome_inner(void *buf, size_t size, InputStream& is, typename enable_if<is_convertible<InputStream, std::istream>::value>::type* = 0)
{
if (size > 0x7fffffff) size = 0x7fffffff;
is.read(static_cast<char *>(buf), size);
const int64_t readSize = is.gcount();
if (readSize < 0) return 0;
if (size == 1 && readSize == 0) is.clear();
return static_cast<size_t>(readSize);
}
/* generic version for size_t readSome(void *, size_t) */
template<class InputStream>
size_t readSome_inner(void *buf, size_t size, InputStream& is, typename enable_if<!is_convertible<InputStream, std::istream>::value>::type* = 0)
{
return is.readSome(buf, size);
}
#else
template<class InputStream>
size_t readSome_inner(void *buf, size_t size, InputStream& is)
{
return is.readSome(buf, size);
}
#endif
#ifndef CYBOZU_DONT_USE_EXCEPTION
/* specialization for ostream */
template<class OutputStream>
void writeSub(OutputStream& os, const void *buf, size_t size, typename enable_if<is_convertible<OutputStream, std::ostream>::value>::type* = 0)
{
if (!os.write(static_cast<const char *>(buf), size)) throw cybozu::Exception("stream:writeSub") << size;
}
#endif
#ifndef CYBOZU_DONT_USE_STRING
/* generic version for void write(const void*, size_t), which writes all data */
template<class OutputStream>
void writeSub(OutputStream& os, const void *buf, size_t size, typename enable_if<!is_convertible<OutputStream, std::ostream>::value>::type* = 0)
{
os.write(buf, size);
}
template<class OutputStream>
void writeSub(bool *pb, OutputStream& os, const void *buf, size_t size, typename enable_if<is_convertible<OutputStream, std::ostream>::value>::type* = 0)
{
*pb = !!os.write(static_cast<const char *>(buf), size);
}
/* generic version for void write(const void*, size_t), which writes all data */
template<class OutputStream>
void writeSub(bool *pb, OutputStream& os, const void *buf, size_t size, typename enable_if<!is_convertible<OutputStream, std::ostream>::value>::type* = 0)
{
os.write(pb, buf, size);
}
#else
template<class OutputStream>
void writeSub(bool *pb, OutputStream& os, const void *buf, size_t size)
{
os.write(pb, buf, size);
}
#endif
} // stream_local
/*
make a specializaiton of class to use new InputStream, OutputStream
*/
template<class InputStream>
struct InputStreamTag {
static size_t readSome(void *buf, size_t size, InputStream& is)
{
return stream_local::readSome_inner<InputStream>(buf, size, is);
}
static bool readChar(char *c, InputStream& is)
{
return readSome(c, 1, is) == 1;
}
};
template<class OutputStream>
struct OutputStreamTag {
static void write(OutputStream& os, const void *buf, size_t size)
{
stream_local::writeSub<OutputStream>(os, buf, size);
}
};
class MemoryInputStream {
const char *p_;
size_t size_;
size_t pos;
public:
MemoryInputStream(const void *p, size_t size) : p_(static_cast<const char *>(p)), size_(size), pos(0) {}
size_t readSome(void *buf, size_t size)
{
if (size > size_ - pos) size = size_ - pos;
memcpy(buf, p_ + pos, size);
pos += size;
return size;
}
size_t getPos() const { return pos; }
};
class MemoryOutputStream {
char *p_;
size_t size_;
size_t pos;
public:
MemoryOutputStream(void *p, size_t size) : p_(static_cast<char *>(p)), size_(size), pos(0) {}
void write(bool *pb, const void *buf, size_t size)
{
if (size > size_ - pos) {
*pb = false;
return;
}
memcpy(p_ + pos, buf, size);
pos += size;
*pb = true;
}
#ifndef CYBOZU_DONT_USE_EXCEPTION
void write(const void *buf, size_t size)
{
bool b;
write(&b, buf, size);
if (!b) throw cybozu::Exception("MemoryOutputStream:write") << size << size_ << pos;
}
#endif
size_t getPos() const { return pos; }
};
#ifndef CYBOZU_DONT_USE_STRING
class StringInputStream {
const std::string& str_;
size_t pos;
StringInputStream(const StringInputStream&);
void operator=(const StringInputStream&);
public:
explicit StringInputStream(const std::string& str) : str_(str), pos(0) {}
size_t readSome(void *buf, size_t size)
{
const size_t remainSize = str_.size() - pos;
if (size > remainSize) size = remainSize;
memcpy(buf, &str_[pos], size);
pos += size;
return size;
}
size_t getPos() const { return pos; }
};
class StringOutputStream {
std::string& str_;
StringOutputStream(const StringOutputStream&);
void operator=(const StringOutputStream&);
public:
explicit StringOutputStream(std::string& str) : str_(str) {}
void write(bool *pb, const void *buf, size_t size)
{
str_.append(static_cast<const char *>(buf), size);
*pb = true;
}
void write(const void *buf, size_t size)
{
str_.append(static_cast<const char *>(buf), size);
}
size_t getPos() const { return str_.size(); }
};
#endif
template<class InputStream>
size_t readSome(void *buf, size_t size, InputStream& is)
{
return stream_local::readSome_inner(buf, size, is);
}
template<class OutputStream>
void write(OutputStream& os, const void *buf, size_t size)
{
stream_local::writeSub(os, buf, size);
}
template<class OutputStream>
void write(bool *pb, OutputStream& os, const void *buf, size_t size)
{
stream_local::writeSub(pb, os, buf, size);
}
template<typename InputStream>
void read(bool *pb, void *buf, size_t size, InputStream& is)
{
char *p = static_cast<char*>(buf);
while (size > 0) {
size_t readSize = cybozu::readSome(p, size, is);
if (readSize == 0) {
*pb = false;
return;
}
p += readSize;
size -= readSize;
}
*pb = true;
}
#ifndef CYBOZU_DONT_USE_EXCEPTION
template<typename InputStream>
void read(void *buf, size_t size, InputStream& is)
{
bool b;
read(&b, buf, size, is);
if (!b) throw cybozu::Exception("stream:read");
}
#endif
template<class InputStream>
bool readChar(char *c, InputStream& is)
{
return readSome(c, 1, is) == 1;
}
template<class OutputStream>
void writeChar(OutputStream& os, char c)
{
cybozu::write(os, &c, 1);
}
template<class OutputStream>
void writeChar(bool *pb, OutputStream& os, char c)
{
cybozu::write(pb, os, &c, 1);
}
} // cybozu