libminifi/src/processors/ExtractText.cpp

/**
 * @file ExtractText.cpp
 * ExtractText class implementation
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include <iterator>
#include <string>
#include <memory>
#include <set>

#include <iostream>
#include <sstream>

#include "processors/ExtractText.h"
#include "core/ProcessContext.h"
#include "core/ProcessSession.h"
#include "core/FlowFile.h"

namespace org {
namespace apache {
namespace nifi {
namespace minifi {
namespace processors {

core::Property ExtractText::Attribute("Attribute", "Attribute to set from content", "");
core::Property ExtractText::SizeLimit("Size Limit", "Maximum number of bytes to read into the attribute. 0 for no limit. Default is 2MB.");
core::Relationship ExtractText::Success("success", "success operational on the flow record");

void ExtractText::initialize() {
    //! Set the supported properties
    std::set<core::Property> properties;
    properties.insert(Attribute);
    setSupportedProperties(properties);
    //! Set the supported relationships
    std::set<core::Relationship> relationships;
    relationships.insert(Success);
    setSupportedRelationships(relationships);
}

void ExtractText::onTrigger(core::ProcessContext *context, core::ProcessSession *session) {
    std::shared_ptr<core::FlowFile> flowFile = session->get();

    if (!flowFile) {
        return;
    }

    ReadCallback cb(flowFile, context);
    session->read(flowFile, &cb);
    session->transfer(flowFile, Success);
}

int64_t ExtractText::ReadCallback::process(std::shared_ptr<io::BaseStream> stream) {
    int64_t ret = 0;
    uint64_t size_limit = flowFile_->getSize();
    uint64_t read_size = 0;
    uint64_t loop_read = max_read_;

    std::string attrKey, sizeLimitStr;
    ctx_->getProperty(Attribute.getName(), attrKey);
    ctx_->getProperty(SizeLimit.getName(), sizeLimitStr);

    if (sizeLimitStr == "")
        size_limit = DEFAULT_SIZE_LIMIT;
    else if (sizeLimitStr != "0")
        size_limit = std::stoi(sizeLimitStr);

    std::ostringstream contentStream;
    std::string contentStr;

    while (read_size < size_limit) {
        if (size_limit - read_size < (uint64_t)max_read_)
            loop_read = size_limit - read_size;

        ret = stream->readData(buffer_, loop_read);
        buffer_.resize(ret);

        if (ret < 0) {
            return -1;
        }

        if (ret > 0) {
            contentStream.write(reinterpret_cast<const char*>(&buffer_[0]), ret);
            if (contentStream.fail()) {
                return -1;
            }
        } else {
            break;
        }
    }

    contentStr = contentStream.str();
    flowFile_->setAttribute(attrKey, contentStr);
    return read_size;
}

ExtractText::ReadCallback::ReadCallback(std::shared_ptr<core::FlowFile> flowFile, core::ProcessContext *ctx)
    : max_read_(getpagesize()),
      flowFile_(flowFile),
      ctx_(ctx) {
          buffer_.resize(max_read_);
      }

} /* namespace processors */
} /* namespace minifi */
} /* namespace nifi */
} /* namespace apache */
} /* namespace org */