oscpkt.hh

/** @mainpage OSCPKT : a minimalistic OSC ( http://opensoundcontrol.org ) c++ library 

  Before using this file please take the time to read the OSC spec, it
  is short and not complicated: http://opensoundcontrol.org/spec-1_0

  Features: 
    - handles basic OSC types: TFihfdsb
    - handles bundles
    - handles OSC pattern-matching rules (wildcards etc in message paths)
    - portable on win / macos / linux
    - robust wrt malformed packets
    - optional udp transport for packets
    - concise, all in a single .h file
    - does not throw exceptions

  does not:
    - take into account timestamp values.
    - provide a cpu-scalable message dispatching.
    - not suitable for use inside a realtime thread as it allocates memory when 
    building or reading messages.


  There are basically 3 classes of interest:
    - oscpkt::Message       : read/write the content of an OSC message
    - oscpkt::PacketReader  : read the bundles/messages embedded in an OSC packet
    - oscpkt::PacketWriter  : write bundles/messages into an OSC packet

  And optionaly:
    - oscpkt::UdpSocket     : read/write OSC packets over UDP.

  @example: oscpkt_demo.cc
  @example: oscpkt_test.cc
*/

/* Copyright (C) 2010  Julien Pommier

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.

  (this is the zlib license)
*/

#ifndef OSCPKT_HH
#define OSCPKT_HH

#ifndef _MSC_VER
#include <stdint.h>
#else
namespace oscpkt {
  typedef __int32 int32_t;
  typedef unsigned __int32 uint32_t;
  typedef __int64 int64_t;
  typedef unsigned __int64 uint64_t;
}
#endif
#include <cstring>
#include <cassert>
#include <string>
#include <vector>
#include <list>

#if defined(OSCPKT_OSTREAM_OUTPUT) || defined(OSCPKT_TEST)
#include <iostream>
#endif

namespace oscpkt {

/**
   OSC timetag stuff, the highest 32-bit are seconds, the lowest are fraction of a second.
*/
class TimeTag {
  uint64_t v;
public:
  TimeTag() : v(1) {}
  explicit TimeTag(uint64_t w): v(w) {}
  operator uint64_t() const { return v; }
  static TimeTag immediate() { return TimeTag(1); }
};

/* the various types that we handle (OSC 1.0 specifies that INT32/FLOAT/STRING/BLOB are the bare minimum) */
enum {
  TYPE_TAG_TRUE = 'T',
  TYPE_TAG_FALSE = 'F',
  TYPE_TAG_INT32 = 'i',
  TYPE_TAG_INT64 = 'h',
  TYPE_TAG_FLOAT = 'f',
  TYPE_TAG_DOUBLE = 'd',
  TYPE_TAG_STRING = 's',
  TYPE_TAG_BLOB = 'b'
};

/* a few utility functions follow.. */
  
// round to the next multiple of 4, works for size_t and pointer arguments
template <typename Type> Type ceil4(Type p) { return (Type)((size_t(p) + 3)&(~size_t(3))); }

// check that a memory area is zero padded until the next address which is a multiple of 4
inline bool isZeroPaddingCorrect(const char *p) {
  const char *q = ceil4(p);
  for (;p < q; ++p)
    if (*p != 0) { return false; }
  return true;
}

// stuff for reading / writing POD ("Plain Old Data") variables to unaligned bytes.
template <typename POD> union PodBytes {
  char bytes[sizeof(POD)];
  POD  value;
};

inline bool isBigEndian() { // a compile-time constant would certainly improve performances..
  PodBytes<int32_t> p; p.value = 0x12345678;
  return p.bytes[0] == 0x12;
}

/** read unaligned bytes into a POD type, assuming the bytes are a little endian representation */
template <typename POD> POD bytes2pod(const char *bytes) {
  PodBytes<POD> p; 
  for (size_t i=0; i < sizeof(POD); ++i) {
    if (isBigEndian()) 
      p.bytes[i] = bytes[i];
    else
      p.bytes[i] = bytes[sizeof(POD) - i - 1];
  }
  return p.value;
}

/** stored a POD type into an unaligned bytes array, using little endian representation */
template <typename POD> void pod2bytes(const POD value, char *bytes) {
  PodBytes<POD> p; p.value = value; 
  for (size_t i=0; i < sizeof(POD); ++i) {
    if (isBigEndian()) 
      bytes[i] = p.bytes[i];
    else
      bytes[i] = p.bytes[sizeof(POD) - i - 1];
  }
}

/** internal stuff, handles the dynamic storage with correct alignments to 4 bytes */
struct Storage {
  std::vector<char> data;
  Storage() { data.reserve(200); }
  char *getBytes(size_t sz) {
    assert((data.size() & 3) == 0);
    if (data.size() + sz > data.capacity()) { data.reserve((data.size() + sz)*2); }
    size_t sz4 = ceil4(sz);
    size_t pos = data.size(); 
    data.resize(pos + sz4); // resize will fill with zeros, so the zero padding is OK
    return &(data[pos]);
  }
  char *begin() { return data.size() ? &data.front() : 0; }
  char *end() { return begin() + size(); }
  const char *begin() const { return data.size() ? &data.front() : 0; }
  const char *end() const { return begin() + size(); }
  size_t size() const { return data.size(); }
  void assign(const char *beg, const char *end) { data.assign(beg, end); }
  void clear() { data.resize(0); }
};

/** check if the path matches the supplied path pattern , according to the OSC spec pattern 
    rules ('*' and '//' wildcards, '{}' alternatives, brackets etc) */
bool fullPatternMatch(const std::string &pattern, const std::string &path);
/** check if the path matches the beginning of pattern */
bool partialPatternMatch(const std::string &pattern, const std::string &path);

#if defined(OSCPKT_DEBUG)
#define OSCPKT_SET_ERR(errcode) do { if (!err) { err = errcode; std::cerr << "set " #errcode << " at line " << __LINE__ << "\n"; } } while (0)
#else
#define OSCPKT_SET_ERR(errcode) do { if (!err) err = errcode; } while (0)
#endif

typedef enum { OK_NO_ERROR=0, 
               // errors raised by the Message class:
               MALFORMED_ADDRESS_PATTERN, MALFORMED_TYPE_TAGS, MALFORMED_ARGUMENTS, UNHANDLED_TYPE_TAGS, 
               // errors raised by ArgReader
               TYPE_MISMATCH, NOT_ENOUGH_ARG, PATTERN_MISMATCH, 
               // errors raised by PacketReader/PacketWriter
               INVALID_BUNDLE, INVALID_PACKET_SIZE, BUNDLE_REQUIRED_FOR_MULTI_MESSAGES } ErrorCode;

/**
   struct used to hold an OSC message that will be written or read.

   The list of arguments is exposed as a sort of queue. You "pop"
   arguments from the front of the queue when reading, you push
   arguments at the back of the queue when writing.

   Many functions return *this, so they can be chained: init("/foo").pushInt32(2).pushStr("kllk")...

   Example of use:

   creation of a message:
   @code
   msg.init("/foo").pushInt32(4).pushStr("bar");
   @endcode
   reading a message, with error detection:
   @code
   if (msg.match("/foo/b*ar/plop")) {
     int i; std::string s; std::vector<char> b;
     if (msg.arg().popInt32(i).popStr(s).popBlob(b).isOkNoMoreArgs()) {
       process message...;
     } else arguments mismatch;
   }
   @endcode
*/
class Message {
  TimeTag time_tag;
  std::string address;
  std::string type_tags;
  std::vector<std::pair<size_t, size_t> > arguments; // array of pairs (pos,size), pos being an index into the 'storage' array.
  Storage storage; // the arguments data is stored here
  ErrorCode err;
public:  
  /** ArgReader is used for popping arguments from a Message, holds a
      pointer to the original Message, and maintains a local error code */
  class ArgReader {
    const Message *msg;
    ErrorCode err;
    size_t arg_idx; // arg index of the next arg that will be popped out.
  public:
    ArgReader(const Message &m, ErrorCode e = OK_NO_ERROR) : msg(&m), err(msg->getErr()), arg_idx(0) { 
      if (e != OK_NO_ERROR && err == OK_NO_ERROR) err=e; 
    }
    ArgReader(const ArgReader &other) : msg(other.msg), err(other.err), arg_idx(other.arg_idx) {}
    bool isBool() { return currentTypeTag() == TYPE_TAG_TRUE || currentTypeTag() == TYPE_TAG_FALSE; }
    bool isInt32() { return currentTypeTag() == TYPE_TAG_INT32; }
    bool isInt64() { return currentTypeTag() == TYPE_TAG_INT64; }
    bool isFloat() { return currentTypeTag() == TYPE_TAG_FLOAT; }
    bool isDouble() { return currentTypeTag() == TYPE_TAG_DOUBLE; }
    bool isStr() { return currentTypeTag() == TYPE_TAG_STRING; }
    bool isBlob() { return currentTypeTag() == TYPE_TAG_BLOB; }

    size_t nbArgRemaining() const { return msg->arguments.size() - arg_idx; }
    bool isOk() const { return err == OK_NO_ERROR; }
    operator bool() const { return isOk(); } // implicit bool conversion is handy here
    /** call this at the end of the popXXX() chain to make sure everything is ok and 
        all arguments have been popped */
    bool isOkNoMoreArgs() const { return err == OK_NO_ERROR && nbArgRemaining() == 0; }
    ErrorCode getErr() const { return err; }

    /** retrieve an int32 argument */
    ArgReader &popInt32(int32_t &i) { return popPod<int32_t>(TYPE_TAG_INT32, i); }
    /** retrieve an int64 argument */
    ArgReader &popInt64(int64_t &i) { return popPod<int64_t>(TYPE_TAG_INT64, i); }
    /** retrieve a single precision floating point argument */
    ArgReader &popFloat(float &f) { return popPod<float>(TYPE_TAG_FLOAT, f); }
    /** retrieve a double precision floating point argument */
    ArgReader &popDouble(double &d) { return popPod<double>(TYPE_TAG_DOUBLE, d); }
    /** retrieve a string argument (no check performed on its content, so it may contain any byte value except 0) */
    ArgReader &popStr(std::string &s) {
      if (precheck(TYPE_TAG_STRING)) {
        s = argBeg(arg_idx++);
      }
      return *this;
    }
    /** retrieve a binary blob */
    ArgReader &popBlob(std::vector<char> &b) { 
      if (precheck(TYPE_TAG_BLOB)) {
        b.assign(argBeg(arg_idx)+4, argEnd(arg_idx)); 
        ++arg_idx;
      }
      return *this;
    }
    /** retrieve a boolean argument */
    ArgReader &popBool(bool &b) {
      b = false;
      if (arg_idx >= msg->arguments.size()) OSCPKT_SET_ERR(NOT_ENOUGH_ARG); 
      else if (currentTypeTag() == TYPE_TAG_TRUE) b = true;
      else if (currentTypeTag() == TYPE_TAG_FALSE) b = false;
      else OSCPKT_SET_ERR(TYPE_MISMATCH);
      ++arg_idx;
      return *this;
    }
    /** skip whatever comes next */
    ArgReader &pop() {
      if (arg_idx >= msg->arguments.size()) OSCPKT_SET_ERR(NOT_ENOUGH_ARG); 
      else ++arg_idx;
      return *this;
    }
  private:
    const char *argBeg(size_t idx) {
      if (err || idx >= msg->arguments.size()) return 0; 
      else return msg->storage.begin() + msg->arguments[idx].first;
    }
    const char *argEnd(size_t idx) {
      if (err || idx >= msg->arguments.size()) return 0; 
      else return msg->storage.begin() + msg->arguments[idx].first + msg->arguments[idx].second;
    }
    int currentTypeTag() {
      if (!err && arg_idx < msg->type_tags.size()) return msg->type_tags[arg_idx];
      else OSCPKT_SET_ERR(NOT_ENOUGH_ARG);
      return -1;
    }
    template <typename POD> ArgReader &popPod(int tag, POD &v) {
      if (precheck(tag)) {
        v = bytes2pod<POD>(argBeg(arg_idx));
        ++arg_idx;
      } else v = POD(0);
      return *this;
    }
    /* pre-check stuff before popping an argument from the message */
    bool precheck(int tag) { 
      if (arg_idx >= msg->arguments.size()) OSCPKT_SET_ERR(NOT_ENOUGH_ARG); 
      else if (!err && currentTypeTag() != tag) OSCPKT_SET_ERR(TYPE_MISMATCH);
      return err == OK_NO_ERROR;
    }
  };

  Message() { clear(); }
  Message(const std::string &s, TimeTag tt = TimeTag::immediate()) : time_tag(tt), address(s), err(OK_NO_ERROR) {}
  Message(const void *ptr, size_t sz, TimeTag tt = TimeTag::immediate()) { buildFromRawData(ptr, sz); time_tag = tt; }

  bool isOk() const { return err == OK_NO_ERROR; }
  ErrorCode getErr() const { return err; }

  /** return the type_tags string, with its initial ',' stripped. */
  const std::string &typeTags() const { return type_tags; }
  /** retrieve the address pattern. If you want to follow to the whole OSC spec, you
      have to handle its matching rules for address specifications -- this file does 
      not provide this functionality */
  const std::string &addressPattern() const { return address; }
  TimeTag timeTag() const { return time_tag; }
  /** clear the message and start a new message with the supplied address and time_tag. */
  Message &init(const std::string &addr, TimeTag tt = TimeTag::immediate()) {
    clear();
    address = addr; time_tag = tt;
    if (address.empty() || address[0] != '/') OSCPKT_SET_ERR(MALFORMED_ADDRESS_PATTERN);     
    return *this;
  }

  /** start a matching test. The typical use-case is to follow this by
      a sequence of calls to popXXX() and a final call to
      isOkNoMoreArgs() which will allow to check that everything went
      fine. For example:
      @code
      if (msg.match("/foo").popInt32(i).isOkNoMoreArgs()) { blah(i); } 
      else if (msg.match("/bar").popStr(s).popInt32(i).isOkNoMoreArgs()) { plop(s,i); }
      else cerr << "unhandled message: " << msg << "\n";
      @endcode
  */
  ArgReader match(const std::string &test) const {
    return ArgReader(*this, fullPatternMatch(address.c_str(), test.c_str()) ? OK_NO_ERROR : PATTERN_MISMATCH);
  }
  /** return true if the 'test' path matched by the first characters of addressPattern().
      For ex. ("/foo/bar").partialMatch("/foo/") is true */
  ArgReader partialMatch(const std::string &test) const {
    return ArgReader(*this, partialPatternMatch(address.c_str(), test.c_str()) ? OK_NO_ERROR : PATTERN_MISMATCH);
  }
  ArgReader arg() const { return ArgReader(*this, OK_NO_ERROR); }

  /** build the osc message for raw data (the message will keep a copy of that data) */
  void buildFromRawData(const void *ptr, size_t sz) {
    clear();
    storage.assign((const char*)ptr, (const char*)ptr + sz);
    const char *address_beg = storage.begin();
    const char *address_end = (const char*)memchr(address_beg, 0, storage.end()-address_beg);
    if (!address_end || !isZeroPaddingCorrect(address_end+1) || address_beg[0] != '/') { 
      OSCPKT_SET_ERR(MALFORMED_ADDRESS_PATTERN); return; 
    } else address.assign(address_beg, address_end);

    const char *type_tags_beg = ceil4(address_end+1);
    const char *type_tags_end = (const char*)memchr(type_tags_beg, 0, storage.end()-type_tags_beg);
    if (!type_tags_end || !isZeroPaddingCorrect(type_tags_end+1) || type_tags_beg[0] != ',') { 
      OSCPKT_SET_ERR(MALFORMED_TYPE_TAGS); return; 
    } else type_tags.assign(type_tags_beg+1, type_tags_end); // we do not copy the initial ','

    const char *arg = ceil4(type_tags_end+1); assert(arg <= storage.end()); 
    size_t iarg = 0;
    while (isOk() && iarg < type_tags.size()) {
      assert(arg <= storage.end()); 
      size_t len = getArgSize(type_tags[iarg], arg);
      if (isOk()) arguments.push_back(std::make_pair(arg - storage.begin(), len));
      arg += ceil4(len); ++iarg;
    }
    if (iarg < type_tags.size() || arg != storage.end()) {
      OSCPKT_SET_ERR(MALFORMED_ARGUMENTS);
    }
  }

  /* below are all the functions that serve when *writing* a message */
  Message &pushBool(bool b) { 
    type_tags += (b ? TYPE_TAG_TRUE : TYPE_TAG_FALSE); 
    arguments.push_back(std::make_pair(storage.size(), storage.size()));
    return *this;
  }
  Message &pushInt32(int32_t i) { return pushPod(TYPE_TAG_INT32, i); }
  Message &pushInt64(int64_t h) { return pushPod(TYPE_TAG_INT64, h); }
  Message &pushFloat(float f) { return pushPod(TYPE_TAG_FLOAT, f); }
  Message &pushDouble(double d) { return pushPod(TYPE_TAG_DOUBLE, d); }
  Message &pushStr(const std::string &s) {
    assert(s.size() < 2147483647); // insane values are not welcome
    type_tags += TYPE_TAG_STRING;
    arguments.push_back(std::make_pair(storage.size(), s.size() + 1));
    strcpy(storage.getBytes(s.size()+1), s.c_str());
    return *this;
  }
  Message &pushBlob(void *ptr, size_t num_bytes) {
    assert(num_bytes < 2147483647); // insane values are not welcome
    type_tags += TYPE_TAG_BLOB; 
    arguments.push_back(std::make_pair(storage.size(), num_bytes+4));
    pod2bytes<int32_t>((int32_t)num_bytes, storage.getBytes(4));
    if (num_bytes)
      memcpy(storage.getBytes(num_bytes), ptr, num_bytes);
    return *this;
  }

  /** reset the message to a clean state */
  void clear() { 
    address.clear(); type_tags.clear(); storage.clear(); arguments.clear(); 
    err = OK_NO_ERROR; time_tag = TimeTag::immediate();
  }

  /** write the raw message data (used by PacketWriter) */
  void packMessage(Storage &s, bool write_size) const {
    if (!isOk()) return;
    size_t l_addr = address.size()+1, l_type = type_tags.size()+2;
    if (write_size) 
      pod2bytes<uint32_t>(uint32_t(ceil4(l_addr) + ceil4(l_type) + ceil4(storage.size())), s.getBytes(4));
    strcpy(s.getBytes(l_addr), address.c_str());
    strcpy(s.getBytes(l_type), ("," + type_tags).c_str());
    if (storage.size())
      memcpy(s.getBytes(storage.size()), const_cast<Storage&>(storage).begin(), storage.size());
  }

private:

  /* get the number of bytes occupied by the argument */
  size_t getArgSize(int type, const char *p) {
    if (err) return 0;
    size_t sz = 0;
    assert(p >= storage.begin() && p <= storage.end());
    switch (type) {
      case TYPE_TAG_TRUE:
      case TYPE_TAG_FALSE: sz = 0; break;
      case TYPE_TAG_INT32: 
      case TYPE_TAG_FLOAT: sz = 4; break;
      case TYPE_TAG_INT64: 
      case TYPE_TAG_DOUBLE: sz = 8; break;
      case TYPE_TAG_STRING: {
        const char *q = (const char*)memchr(p, 0, storage.end()-p);
        if (!q) OSCPKT_SET_ERR(MALFORMED_ARGUMENTS);
        else sz = (q-p)+1;
      } break;
      case TYPE_TAG_BLOB: {
        if (p == storage.end()) { OSCPKT_SET_ERR(MALFORMED_ARGUMENTS); return 0; }
        sz = 4+bytes2pod<uint32_t>(p);
      } break;
      default: {
        OSCPKT_SET_ERR(UNHANDLED_TYPE_TAGS); return 0;
      } break;
    }
    if (p+sz > storage.end() || /* string or blob too large.. */
        p+sz < p /* or even blob so large that it did overflow */) { 
      OSCPKT_SET_ERR(MALFORMED_ARGUMENTS); return 0; 
    }
    if (!isZeroPaddingCorrect(p+sz)) { OSCPKT_SET_ERR(MALFORMED_ARGUMENTS); return 0; }
    return sz;
  }

  template <typename POD> Message &pushPod(int tag, POD v) {
    type_tags += (char)tag; 
    arguments.push_back(std::make_pair(storage.size(), sizeof(POD)));
    pod2bytes(v, storage.getBytes(sizeof(POD))); 
    return *this;
  }

#ifdef OSCPKT_OSTREAM_OUTPUT
  friend std::ostream &operator<<(std::ostream &os, const Message &msg) {
    os << "osc_address: '" << msg.address << "', types: '" << msg.type_tags << "', timetag=" << msg.time_tag << ", args=[";
    Message::ArgReader arg(msg);
    while (arg.nbArgRemaining() && arg.isOk()) {
      if (arg.isBool()) { bool b; arg.popBool(b); os << (b?"True":"False"); }
      else if (arg.isInt32()) { int32_t i; arg.popInt32(i); os << i; }
      else if (arg.isInt64()) { int64_t h; arg.popInt64(h); os << h << "ll"; }
      else if (arg.isFloat()) { float f; arg.popFloat(f); os << f << "f"; }
      else if (arg.isDouble()) { double d; arg.popDouble(d); os << d; }
      else if (arg.isStr()) { std::string s; arg.popStr(s); os << "'" << s << "'"; }
      else if (arg.isBlob()) { std::vector<char> b; arg.popBlob(b); os << "Blob " << b.size() << " bytes"; }
      else {
        assert(0); // I forgot a case..
      }
      if (arg.nbArgRemaining()) os << ", ";
    }
    if (!arg.isOk()) { os << " ERROR#" << arg.getErr(); }
    os << "]";
    return os;
  }
#endif
};

/**
   parse an OSC packet and extracts the embedded OSC messages. 
*/
class PacketReader {
public:
  PacketReader() { err = OK_NO_ERROR; }
  /** pointer and size of the osc packet to be parsed. */
  PacketReader(const void *ptr, size_t sz) { init(ptr, sz); }

  void init(const void *ptr, size_t sz) {
    err = OK_NO_ERROR; messages.clear();
    if ((sz%4) == 0) { 
      parse((const char*)ptr, (const char *)ptr+sz, TimeTag::immediate());
    } else OSCPKT_SET_ERR(INVALID_PACKET_SIZE);
    it_messages = messages.begin();
  }
  
  /** extract the next osc message from the packet. return 0 when all messages have been read, or in case of error. */
  Message *popMessage() {
    if (!err && !messages.empty() && it_messages != messages.end()) return &*it_messages++;
    else return 0;
  }
  bool isOk() const { return err == OK_NO_ERROR; }
  ErrorCode getErr() const { return err; }

private:
  std::list<Message> messages;
  std::list<Message>::iterator it_messages;
  ErrorCode err;
  
  void parse(const char *beg, const char *end, TimeTag time_tag) {
    assert(beg <= end && !err); assert(((end-beg)%4)==0);
    
    if (beg == end) return;
    if (*beg == '#') {
      /* it's a bundle */
      if (end - beg >= 20 
          && memcmp(beg, "#bundle\0", 8) == 0) {
        TimeTag time_tag2(bytes2pod<uint64_t>(beg+8));
        const char *pos = beg + 16;
        do {
          uint32_t sz = bytes2pod<uint32_t>(pos); pos += 4;
          if ((sz&3) != 0 || pos + sz > end || pos+sz < pos) {
            OSCPKT_SET_ERR(INVALID_BUNDLE);
          } else {
            parse(pos, pos+sz, time_tag2);
            pos += sz;
          }
        } while (!err && pos != end);
      } else {
        OSCPKT_SET_ERR(INVALID_BUNDLE);
      }
    } else {
      messages.push_back(Message(beg, end-beg, time_tag));
      if (!messages.back().isOk()) OSCPKT_SET_ERR(messages.back().getErr());
    }
  }
};


/**
   Assemble messages into an OSC packet. Example of use:
   @code
   PacketWriter pkt; 
   Message msg;
   pkt.startBundle(); 
   pkt.addMessage(msg.init("/foo").pushBool(true).pushStr("plop").pushFloat(3.14f));
   pkt.addMessage(msg.init("/bar").pushBool(false));
   pkt.endBundle();
   if (pkt.isOk()) {
     send(pkt.data(), pkt.size());
   }
   @endcode
*/
class PacketWriter {
public:
  PacketWriter() { init(); }
  PacketWriter &init() { err = OK_NO_ERROR; storage.clear(); bundles.clear(); return *this; }
  
  /** begin a new bundle. If you plan to pack more than one message in the Osc packet, you have to 
      put them in a bundle. Nested bundles inside bundles are also allowed. */
  PacketWriter &startBundle(TimeTag ts = TimeTag::immediate()) {
    char *p;
    if (bundles.size()) storage.getBytes(4); // hold the bundle size
    p = storage.getBytes(8); strcpy(p, "#bundle"); bundles.push_back(p - storage.begin());
    p = storage.getBytes(8); pod2bytes<uint64_t>(ts, p);
    return *this;
  }
  /** close the current bundle. */
  PacketWriter &endBundle() {
    if (bundles.size()) {
      if (storage.size() - bundles.back() == 16) {
        pod2bytes<uint32_t>(0, storage.getBytes(4)); // the 'empty bundle' case, not very elegant
      }
      if (bundles.size()>1) { // no size stored for the top-level bundle
        pod2bytes<uint32_t>(uint32_t(storage.size() - bundles.back()), storage.begin() + bundles.back()-4);
      }
      bundles.pop_back();      
    } else OSCPKT_SET_ERR(INVALID_BUNDLE);
    return *this;
  }

  /** insert an Osc message into the current bundle / packet.
   */
  PacketWriter &addMessage(const Message &msg) {
    if (storage.size() != 0 && bundles.empty()) OSCPKT_SET_ERR(BUNDLE_REQUIRED_FOR_MULTI_MESSAGES);
    else msg.packMessage(storage, bundles.size()>0);
    if (!msg.isOk()) OSCPKT_SET_ERR(msg.getErr());
    return *this;
  }

  /** the error flag will be raised if an opened bundle is not closed, or if more than one message is
      inserted in the packet without a bundle */
  bool isOk() { return err == OK_NO_ERROR; }
  ErrorCode getErr() { return err; }

  /** return the number of bytes of the osc packet -- will always be a
      multiple of 4 -- returns 0 if the construction of the packet has
      failed. */
  uint32_t packetSize() { return err ? 0 : (uint32_t)storage.size(); }
  
  /** return the bytes of the osc packet (NULL if the construction of the packet has failed) */
  char *packetData() { return err ? 0 : storage.begin(); }
private:  
  std::vector<size_t> bundles; // hold the position in the storage array of the beginning marker of each bundle
  Storage storage;
  ErrorCode err;
};

// see the OSC spec for the precise pattern matching rules
inline const char *internalPatternMatch(const char *pattern, const char *path) {
  while (*pattern) {
    const char *p = pattern;
    if (*p == '?' && *path) { ++p; ++path; }
    else if (*p == '[' && *path) { // bracketted range, e.g. [a-zABC]
      ++p;
      bool reverse = false;
      if (*p == '!') { reverse = true; ++p; }
      bool match = reverse;
      for (; *p && *p != ']'; ++p) {
        char c0 = *p, c1 = c0;
        if (p[1] == '-' && p[2] && p[2] != ']') { p += 2; c1 = *p; }
        if (*path >= c0 && *path <= c1) { match = !reverse; }
      }
      if (!match || *p != ']') return pattern;
      ++p; ++path;
    } else if (*p == '*') { // wildcard '*'
      while (*p == '*') ++p; 
      const char *best = 0;
      while (true) {
        const char *ret = internalPatternMatch(p, path);
        if (ret && ret > best) best = ret;
        if (*path == 0 || *path == '/') break;
        else ++path;
      }
      return best;
    } else if (*p == '/' && *(p+1) == '/') { // the super-wildcard '//'
      while (*(p+1)=='/') ++p;
      const char *best = 0;
      while (true) {
        const char *ret = internalPatternMatch(p, path);
        if (ret && ret > best) best = ret;
        if (*path == 0) break;
        if (*path == 0 || (path = strchr(path+1, '/')) == 0) break;
      }      
      return best;
    } else if (*p == '{') { // braced list {foo,bar,baz}
      const char *end = strchr(p, '}'), *q;
      if (!end) return 0; // syntax error in brace list..
      bool match = false;
      do {
        ++p;
        q = strchr(p, ',');
        if (q == 0 || q > end) q = end;
        if (strncmp(p, path, q-p)==0) {
          path += (q-p); p = end+1; match = true;
        } else p=q;
      } while (q != end && !match);
      if (!match) return pattern;
    } else if (*p == *path) { ++p; ++path; } // any other character
    else break;
    pattern = p;
  }
  return (*path == 0 ? pattern : 0);
}

inline bool partialPatternMatch(const std::string &pattern, const std::string &test) {
  const char *q = internalPatternMatch(pattern.c_str(), test.c_str());
  return q != 0;
}

inline bool fullPatternMatch(const std::string &pattern, const std::string &test) {
  const char *q = internalPatternMatch(pattern.c_str(), test.c_str());
  return q && *q == 0;
}

} // namespace oscpkt

#endif // OSCPKT_HH