plugins/slice/Data.h

/** @file
  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.
 */

#pragma once

#include "ts/ts.h"

#include "HttpHeader.h"
#include "Range.h"
#include "Stage.h"

#include <netinet/in.h>
#include <string>
#include <unordered_map>

struct Config;

enum BlockState {
  Pending,    // waiting for response
  Active,     // processing current block
  PendingRef, // waiting for reference refetch response
  ActiveRef,  // processing current reference refetch
  Done,
  Passthru, // non 206 response passthru
  Fail,
};

struct Data {
  Data(Data const &)            = delete;
  Data &operator=(Data const &) = delete;

  Config *const m_config;

  sockaddr_storage m_client_ip;

  // cached effective URL for use during async intercept processing
  std::string m_effective_url;

  // for pristine/effective url coming in
  TSMBuffer m_urlbuf{nullptr};
  TSMLoc    m_urlloc{nullptr};

  char m_hostname[8192];
  int  m_hostlen{0};

  // best identifier headers, initially from reference slice
  char m_etag[8192];
  int  m_etaglen{0};
  char m_lastmodified[33];
  int  m_lastmodifiedlen{0};

  int64_t m_contentlen{-1};

  TSHttpStatus m_statustype{TS_HTTP_STATUS_NONE}; // 200 or 206

  const char *m_method_type{nullptr}; // type of header request

  Range m_req_range; // converted to half open interval

  int64_t m_blocknum{-1};     // block number to work on, -1 bad/stop
  int64_t m_blockexpected{0}; // body bytes expected
  int64_t m_blockskip{0};     // number of bytes to skip in this block
  int64_t m_blockconsumed{0}; // body bytes consumed

  int64_t      m_purge_hits{0};                    // blocks a purge actually removed
  int          m_purge_misses{0};                  // consecutive uncached blocks the walk has seen
  int          m_purge_miss_bound{0};              // from the config or the request header
  TSHttpStatus m_purge_error{TS_HTTP_STATUS_NONE}; // block failure that ended the walk

  BlockState m_blockstate{Pending}; // is there an active slice block

  int64_t m_bytestosend{0}; // header + content bytes to send
  int64_t m_bytessent{0};   // number of bytes written to the client

  // default buffer size and water mark
  TSIOBufferSizeIndex m_buffer_index{TS_IOBUFFER_SIZE_INDEX_32K};
  TSIOBufferWaterMark m_buffer_water_mark{TS_IOBUFFER_WATER_MARK_PLUGIN_VC_DEFAULT};

  bool m_server_block_header_parsed{false};
  bool m_server_first_header_parsed{false};

  Stage m_upstream;
  Stage m_dnstream;

  bool m_prefetchable{false};

  int64_t m_prefetch_hwm{-1}; // highest block this request has scheduled for prefetch

  HdrMgr m_req_hdrmgr;  // manager for server request
  HdrMgr m_resp_hdrmgr; // manager for client response

  TSHttpParser m_http_parser{nullptr}; //!< cached for reuse

  explicit Data(Config *const config) : m_config(config)
  {
    m_hostname[0]     = '\0';
    m_etag[0]         = '\0';
    m_lastmodified[0] = '\0';
    memset(&m_client_ip, 0, sizeof(m_client_ip));
  }

  // HEAD only; a purge sends just a header too but never reaches the transfer path
  bool
  onlyHeader() const
  {
    return m_method_type == TS_HTTP_METHOD_HEAD;
  }

  bool
  is_purge() const
  {
    return m_method_type == TS_HTTP_METHOD_PURGE;
  }

  // The purge range, closed against the object length once known. m_req_range
  // stays as sent so a longer extent can widen the walk; a clamp could only shrink.
  Range
  purge_range() const
  {
    return (m_contentlen < 0) ? m_req_range : m_req_range.intersectedWith(Range(0, m_contentlen));
  }

  ~Data()
  {
    if (nullptr != m_urlbuf) {
      if (nullptr != m_urlloc) {
        TSHandleMLocRelease(m_urlbuf, TS_NULL_MLOC, m_urlloc);
        m_urlloc = nullptr;
      }
      TSMBufferDestroy(m_urlbuf);
      m_urlbuf = nullptr;
    }
    if (nullptr != m_http_parser) {
      TSHttpParserDestroy(m_http_parser);
      m_http_parser = nullptr;
    }
  }
};