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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
/**
* Copyright (C) 2013 Regents of the University of California.
* @author: Jeff Thompson <jefft0@remap.ucla.edu>
* @author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
* @author: Zhenkai Zhu <zhenkai@cs.ucla.edu>
* See COPYING for copyright and distribution information.
*/
#ifndef NDN_NAME_COMPONENT_HPP
#define NDN_NAME_COMPONENT_HPP
#include "common.hpp"
#include "encoding/block.hpp"
#include "encoding/encoding-buffer.hpp"
#include "util/string-helper.hpp"
namespace ndn {
namespace name {
/**
* A Name::Component holds a read-only name component value.
*/
class Component : public Block
{
public:
/**
* @brief Error that can be thrown from the block
*/
class Error : public std::runtime_error
{
public:
explicit
Error(const std::string& what)
: std::runtime_error(what)
{
}
};
/**
* Create a new Name::Component with a null value.
*/
Component();
/**
* @brief Directly create component from wire block
*
* Any block can be implicitly converted to name::Component
*
* @throws Error if wire.type() is not Tlv::Component
*/
Component(const Block& wire);
/**
* Create a new Name::Component, taking another pointer to the Blob value.
* @param value A blob with a pointer to an immutable array. The pointer is copied.
*/
explicit
Component(const ConstBufferPtr& buffer);
/**
* Create a new Name::Component, copying the given value.
* @param value The value byte array.
*/
explicit
Component(const Buffer& value);
/**
* Create a new Name::Component, copying the given value.
* @param value Pointer to the value byte array.
* @param valueLen Length of value.
*/
Component(const uint8_t* value, size_t valueLen);
template<class InputIterator>
Component(InputIterator begin, InputIterator end);
explicit
Component(const char* str);
explicit
Component(const std::string& str);
/**
* @brief Fast encoding or block size estimation
*/
template<bool T>
size_t
wireEncode(EncodingImpl<T>& block) const;
/**
* @brief Encode to a wire format
*/
inline const Block&
wireEncode() const;
/**
* @brief Decode from the wire format
*/
inline void
wireDecode(const Block& wire);
/**
* Make a Blob value by decoding the escapedString between beginOffset and endOffset according to the NDN URI Scheme.
* If the escaped string is "", "." or ".." then return a Blob with a null pointer,
* which means the component should be skipped in a URI name.
* @param escapedString The escaped string. It does not need to be null-terminated because we only scan to endOffset.
* @param beginOffset The offset in escapedString of the beginning of the portion to decode.
* @param endOffset The offset in escapedString of the end of the portion to decode.
* @return The Blob value. If the escapedString is not a valid escaped component, then the Blob is a null pointer.
*/
static Component
fromEscapedString(const char* escapedString, size_t beginOffset, size_t endOffset);
/**
* Make a Blob value by decoding the escapedString according to the NDN URI Scheme.
* If the escaped string is "", "." or ".." then return a Blob with a null pointer,
* which means the component should be skipped in a URI name.
* @param escapedString The null-terminated escaped string.
* @return The Blob value. If the escapedString is not a valid escaped component, then the Blob is a null pointer.
*/
static Component
fromEscapedString(const char* escapedString)
{
return fromEscapedString(escapedString, 0, ::strlen(escapedString));
}
/**
* Make a Blob value by decoding the escapedString according to the NDN URI Scheme.
* If the escaped string is "", "." or ".." then return a Blob with a null pointer,
* which means the component should be skipped in a URI name.
* @param escapedString The escaped string.
* @return The Blob value. If the escapedString is not a valid escaped component, then the Blob is a null pointer.
*/
static Component
fromEscapedString(const std::string& escapedString)
{
return fromEscapedString(escapedString.c_str());
}
/**
* Write the value to result, escaping characters according to the NDN URI Scheme.
* This also adds "..." to a value with zero or more ".".
* @param value the buffer with the value to escape
* @param result the string stream to write to.
*/
void
toEscapedString(std::ostream& result) const;
/**
* Convert the value by escaping characters according to the NDN URI Scheme.
* This also adds "..." to a value with zero or more ".".
* @param value the buffer with the value to escape
* @return The escaped string.
*/
inline std::string
toEscapedString() const
{
std::ostringstream result;
toEscapedString(result);
return result.str();
}
inline void
toUri(std::ostream& result) const
{
return toEscapedString(result);
}
inline std::string
toUri() const
{
return toEscapedString();
}
/**
* @brief Interpret this name component as nonNegativeInteger
*
* @see http://named-data.net/doc/ndn-tlv/tlv.html#non-negative-integer-encoding
*
* @return The integer number.
*/
uint64_t
toNumber() const;
/**
* @brief An alias for toNumber()
*/
uint64_t
toVersion() const;
/**
* @brief An alias for toNumber()
*/
uint64_t
toSegment() const;
/**
* @brief Create a component encoded as nonNegativeInteger
*
* @see http://named-data.net/doc/ndn-tlv/tlv.html#non-negative-integer-encoding
*
* @param number The non-negative number
* @return The component value.
*/
static Component
fromNumber(uint64_t number);
/**
* Check if this is the same component as other.
* @param other The other Component to compare with.
* @return true if the components are equal, otherwise false.
*/
bool
equals(const Component& other) const
{
if (value_size() != other.value_size())
return false;
if (value_size() == 0 /* == other.value_size()*/)
return true;
// somehow, behavior is wrong on OSX 10.9 when component is empty
// (probably some bug in STL...)
return std::equal(value_begin(), value_end(), other.value_begin());
}
bool
empty() const
{
return !hasValue();
}
/**
* Check if this is the same component as other.
* @param other The other Component to compare with.
* @return true if the components are equal, otherwise false.
*/
bool
operator==(const Component& other) const { return equals(other); }
/**
* Check if this is not the same component as other.
* @param other The other Component to compare with.
* @return true if the components are not equal, otherwise false.
*/
bool
operator!=(const Component& other) const { return !equals(other); }
/**
* Compare this to the other Component using NDN canonical ordering.
* @param other The other Component to compare with.
* @return 0 If they compare equal, -1 if *this comes before other in the canonical ordering, or
* 1 if *this comes after other in the canonical ordering.
*
* @see http://named-data.net/doc/ndn-tlv/name.html#canonical-order
*/
int
compare(const Component& other) const;
/**
* Return true if this is less than or equal to the other Component in the NDN canonical ordering.
* @param other The other Component to compare with.
*
* @see http://named-data.net/doc/ndn-tlv/name.html#canonical-order
*/
bool
operator<=(const Component& other) const { return compare(other) <= 0; }
/**
* Return true if this is less than the other Component in the NDN canonical ordering.
* @param other The other Component to compare with.
*
* @see http://named-data.net/doc/ndn-tlv/name.html#canonical-order
*/
bool
operator<(const Component& other) const { return compare(other) < 0; }
/**
* Return true if this is less than or equal to the other Component in the NDN canonical ordering.
* @param other The other Component to compare with.
*
* @see http://named-data.net/doc/ndn-tlv/name.html#canonical-order
*/
bool
operator>=(const Component& other) const { return compare(other) >= 0; }
/**
* Return true if this is greater than the other Component in the NDN canonical ordering.
* @param other The other Component to compare with.
*
* @see http://named-data.net/doc/ndn-tlv/name.html#canonical-order
*/
bool
operator>(const Component& other) const { return compare(other) > 0; }
//
// !!! MUST NOT INCLUDE ANY DATA HERE !!!
//
// This class is just a helper and is directly reinterpret_cast'ed from Block
};
inline std::ostream&
operator << (std::ostream& os, const Component& component)
{
component.toEscapedString(os);
return os;
}
inline
Component::Component()
: Block(Tlv::NameComponent)
{
}
inline
Component::Component(const Block& wire)
: Block(wire)
{
if (type() != Tlv::NameComponent)
throw Error("Constructing name component from non name component TLV wire block");
}
inline
Component::Component(const ConstBufferPtr& buffer)
: Block (Tlv::NameComponent, buffer)
{
}
inline
Component::Component(const Buffer& value)
: Block (Tlv::NameComponent, ConstBufferPtr(new Buffer(value)))
{
}
inline
Component::Component(const uint8_t* value, size_t valueLen)
: Block (Tlv::NameComponent, ConstBufferPtr(new Buffer(value, valueLen)))
{
}
template<class InputIterator>
inline
Component::Component(InputIterator begin, InputIterator end)
: Block (Tlv::NameComponent, ConstBufferPtr(new Buffer(begin, end)))
{
}
inline
Component::Component(const char* str)
: Block (Tlv::NameComponent, ConstBufferPtr(new Buffer(str, ::strlen(str))))
{
}
inline
Component::Component(const std::string& str)
: Block (Tlv::NameComponent, ConstBufferPtr(new Buffer(str.begin(), str.end())))
{
}
inline Component
Component::fromEscapedString(const char* escapedString, size_t beginOffset, size_t endOffset)
{
std::string trimmedString(escapedString + beginOffset, escapedString + endOffset);
trim(trimmedString);
std::string value = unescape(trimmedString);
if (value.find_first_not_of(".") == std::string::npos) {
// Special case for component of only periods.
if (value.size() <= 2)
// Zero, one or two periods is illegal. Ignore this component.
return Component();
else
// Remove 3 periods.
return Component(reinterpret_cast<const uint8_t*>(&value[3]), value.size() - 3);
}
else
return Component(reinterpret_cast<const uint8_t*>(&value[0]), value.size());
}
inline void
Component::toEscapedString(std::ostream& result) const
{
const uint8_t* valuePtr = value();
size_t valueSize = value_size();
bool gotNonDot = false;
for (unsigned i = 0; i < valueSize; ++i) {
if (valuePtr[i] != 0x2e) {
gotNonDot = true;
break;
}
}
if (!gotNonDot) {
// Special case for component of zero or more periods. Add 3 periods.
result << "...";
for (size_t i = 0; i < valueSize; ++i)
result << '.';
}
else {
// In case we need to escape, set to upper case hex and save the previous flags.
std::ios::fmtflags saveFlags = result.flags(std::ios::hex | std::ios::uppercase);
for (size_t i = 0; i < valueSize; ++i) {
uint8_t x = valuePtr[i];
// Check for 0-9, A-Z, a-z, (+), (-), (.), (_)
if ((x >= 0x30 && x <= 0x39) || (x >= 0x41 && x <= 0x5a) ||
(x >= 0x61 && x <= 0x7a) || x == 0x2b || x == 0x2d ||
x == 0x2e || x == 0x5f)
result << x;
else {
result << '%';
if (x < 16)
result << '0';
result << (unsigned int)x;
}
}
// Restore.
result.flags(saveFlags);
}
}
inline Component
Component::fromNumber(uint64_t number)
{
/// \todo Change to Tlv::NumberComponent
return nonNegativeIntegerBlock(Tlv::NameComponent, number);
}
inline uint64_t
Component::toNumber() const
{
/// \todo Check if Component is of Tlv::NumberComponent type
return readNonNegativeInteger(static_cast<const Block&>(*this));
}
inline uint64_t
Component::toVersion() const
{
return toNumber();
}
inline uint64_t
Component::toSegment() const
{
return toNumber();
}
inline int
Component::compare(const Component& other) const
{
// Imitate ndn_Exclude_compareComponents.
if (value_size() < other.value_size())
return -1;
if (value_size() > other.value_size())
return 1;
if (value_size() == 0)
return 0;
// The components are equal length. Just do a byte compare.
return std::memcmp(value(), other.value(), value_size());
}
template<bool T>
inline size_t
Component::wireEncode(EncodingImpl<T>& block) const
{
size_t totalLength = 0;
if (value_size() > 0)
totalLength += block.prependByteArray (value(), value_size());
totalLength += block.prependVarNumber (value_size());
totalLength += block.prependVarNumber (Tlv::NameComponent);
return totalLength;
}
/**
* @brief Encode to a wire format
*/
inline const Block&
Component::wireEncode() const
{
if (this->hasWire())
return *this;
EncodingEstimator estimator;
size_t estimatedSize = wireEncode(estimator);
EncodingBuffer buffer(estimatedSize, 0);
wireEncode(buffer);
const_cast<Component&>(*this) = buffer.block();
return *this;
}
/**
* @brief Decode from the wire format
*/
inline void
Component::wireDecode(const Block& wire)
{
if (wire.type() != Tlv::NameComponent)
throw Error("wireDecode name component from non name component TLV wire block");
*this = wire;
}
} // namespace name
} // namespace ndn
#endif // NDN_NAME_COMPONENT_HPP