XMLProtocolInfoParser.h

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// Lightweight streaming parser for ConnectionManager GetProtocolInfo responses
#pragma once
 
#include <functional>
 
#include "basic/Str.h"
#include "dlna/common/Action.h"
#include "http/Server/HttpRequest.h"
// Client from Arduino core
#include <Client.h>
 
namespace tiny_dlna {
 
class XMLProtocolInfoParser {
 public:
  static bool parse(
      Stream& in,
      std::function<void(const char* entry, ProtocolRole role)> cb) {
    if ( !cb) return false;
 
    enum CollectState { LOOKING, IN_SOURCE, IN_SINK } state = LOOKING;
    Str token(128);
    const char* endSource = "</Source>";
    const char* endSink = "</Sink>";
    int matchPos = 0;
 
    uint8_t buf[200];
    while (true) {
      int len = in.readBytes(buf, sizeof(buf));
      if (len <= 0) break;
      for (int i = 0; i < len; ++i) {
        char c = (char)buf[i];
        if (state == LOOKING) {
          static Str openBuf(16);
          openBuf.add(c);
          if (openBuf.length() > 64)
            openBuf =
                openBuf.substring(openBuf.length() - 64, openBuf.length());
          if (openBuf.indexOf("<Source") >= 0) {
            state = IN_SOURCE;
            token.clear();
            matchPos = 0;
            openBuf.clear();
            continue;
          }
          if (openBuf.indexOf("<Sink") >= 0) {
            state = IN_SINK;
            token.clear();
            matchPos = 0;
            openBuf.clear();
            continue;
          }
        } else if (state == IN_SOURCE) {
          if (c == endSource[matchPos]) {
            matchPos++;
            if (endSource[matchPos] == '\0') {
              Str t = token;
              t.trim();
              if (!t.isEmpty()) cb(t.c_str(), (ProtocolRole)0);
              token.clear();
              state = LOOKING;
              matchPos = 0;
              continue;
            }
            continue;
          } else {
            if (matchPos > 0) {
              for (int k = 0; k < matchPos; ++k) token.add(endSource[k]);
              matchPos = 0;
            }
            if (c == ',') {
              Str t = token;
              t.trim();
              if (!t.isEmpty()) cb(t.c_str(), (ProtocolRole)0);
              token.clear();
            } else {
              token.add(c);
            }
          }
        } else if (state == IN_SINK) {
          if (c == endSink[matchPos]) {
            matchPos++;
            if (endSink[matchPos] == '\0') {
              Str t = token;
              t.trim();
              if (!t.isEmpty()) cb(t.c_str(), (ProtocolRole)1);
              token.clear();
              state = LOOKING;
              matchPos = 0;
              continue;
            }
            continue;
          } else {
            if (matchPos > 0) {
              for (int k = 0; k < matchPos; ++k) token.add(endSink[k]);
              matchPos = 0;
            }
            if (c == ',') {
              Str t = token;
              t.trim();
              if (!t.isEmpty()) cb(t.c_str(), (ProtocolRole)1);
              token.clear();
            } else {
              token.add(c);
            }
          }
        }
      }
    }
 
    if (state == IN_SOURCE) {
      Str t = token;
      t.trim();
      if (!t.isEmpty()) cb(t.c_str(), (ProtocolRole)0);
    } else if (state == IN_SINK) {
      Str t = token;
      t.trim();
      if (!t.isEmpty()) cb(t.c_str(), (ProtocolRole)1);
    }
 
    return true;
  }
};
 
}  // namespace tiny_dlna