proxy/Prefetch.h

/** @file

  A brief file description

  @section license License

  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.
 */

#ifndef _PREFETCH_H_
#define _PREFETCH_H_

#include "IPRange.h"
#include "TransformInternal.h"

#ifdef PREFETCH

#include "Update.h"
#include "api/ts/experimental.h"
#include "api/ts/InkAPIHughes.h"

#define IPSTRARGS(ip) (unsigned int) ((unsigned char *) &(ip))[0],	\
		      (unsigned int) ((unsigned char *) &(ip))[1],	\
	              (unsigned int) ((unsigned char *) &(ip))[2],	\
	              (unsigned int) ((unsigned char *) &(ip))[3]

typedef enum
{
  ILL_BLAST = 0,
  UDP_BLAST = TS_PREFETCH_PROTO_UDP,
  TCP_BLAST = TS_PREFETCH_PROTO_TCP
    //MULTICAST_BLAST = TS_PREFETCH_PROTO_UDP_MULTICAST
} PrefetchBlastType;

class BlasterUrlList;
class PrefetchUrlBlaster;
class PrefetchBlaster;
extern BlasterUrlList *multicastUrlBlaster;

struct PrefetchConfiguration
{
  int prefetch_enabled;
  IPRange ip_range;
  struct html_tag *html_tags_table;
  struct html_tag *html_attrs_table;

  int local_http_server_port;
  int stuffer_port;

  int url_buffer_size;
  int url_buffer_timeout;

  unsigned int default_url_proto;
  unsigned int default_data_proto;

  int keepalive_timeout;
  int push_cached_objects;

  unsigned int max_object_size;

  unsigned int max_recursion;   //limit on depth of recursive prefetch
  unsigned int redirection;     //limit on depth of redirect prefetch

  TSPrefetchHook pre_parse_hook;
  TSPrefetchHook embedded_url_hook;
  TSPrefetchHook embedded_obj_hook;

  int readConfiguration();
  void readHtmlTags(int fd, html_tag ** ptags, html_tag ** pattrs);
};

// TODO: This used to be private, which seems wrong.
class PrefetchUrlEntry: public RefCountObj
{
public:
  PrefetchUrlEntry()
    : url(0), len(INT_MAX), resp_blaster(0),
      object_buf_status(TS_PREFETCH_OBJ_BUF_NOT_NEEDED),
      req_ip(0), child_ip(0), url_multicast_ip(0), data_multicast_ip(0), blaster_link(0), hash_link(0)
  {
    refcount_inc();
  }

  void init(char *str, INK_MD5 & xmd5)
  {
    len = strlen(url = str) + 1;
    md5 = xmd5;
  }
  void free();

  PrefetchUrlEntry *assign()
  {
    refcount_inc();
    return this;
  };

  char *url;
  int len;
  INK_MD5 md5;

  //PrefetchBlastType   resp_blast_proto;
  //HTTPHdr *           request;
  PrefetchBlaster *resp_blaster;

  int object_buf_status;

  uint32_t req_ip;                /*ip address where request is coming from */
  uint32_t child_ip;
  uint32_t url_multicast_ip;
  uint32_t data_multicast_ip;

  PrefetchUrlEntry *blaster_link;
  PrefetchUrlEntry *hash_link;

private:
  // this private copy ctor is set to prevent from being used
  // coverity[uninit_member]
  PrefetchUrlEntry(const PrefetchUrlEntry &)
  {
  };
};

extern ClassAllocator<PrefetchUrlEntry> prefetchUrlEntryAllocator;

inline void
PrefetchUrlEntry::free()
{
  if (refcount_dec() == 0) {
    if (url)
      xfree(url);
    prefetchUrlEntryAllocator.free(this);
  }
}

class PrefetchTransform:public INKVConnInternal, public RefCountObj
{
  enum
  { HASH_TABLE_LENGTH = 61 /*127, 511 */  };
public:

    PrefetchTransform(HttpSM * sm, HTTPHdr * resp);
   ~PrefetchTransform();
  void free()
  {
    if (refcount_dec() == 0)
      delete this;
  };
  PrefetchTransform *assign()
  {
    refcount_inc();
    return this;
  };

  int handle_event(int event, void *edata);
  int parse_data(IOBufferReader * reader);
  int redirect(HTTPHdr * resp);

  PrefetchUrlEntry *hash_add(char *url);

public:
  MIOBuffer * m_output_buf;
  IOBufferReader *m_output_reader;
  VIO *m_output_vio;

  HttpSM *m_sm;
  //HTTPHdr *m_request;
  //HTTPHdr *m_response;

  char *url;

  //unsigned int                child_ip;
  HtmlParser html_parser;

  PrefetchUrlEntry *hash_table[HASH_TABLE_LENGTH];

  BlasterUrlList *udp_url_list;
  BlasterUrlList *tcp_url_list;

  const char *domain_start;
  const char *domain_end;
  const char *host_start;
  int host_len;
  bool no_dot_in_host;
};


//blaster
class BlasterUrlList:public Continuation
{

  int timeout;                  //in milliseconds
  Action *action;
  int mtu;
  PrefetchBlastType blast_proto;

  PrefetchUrlEntry *list_head;
  int cur_len;

public:
  BlasterUrlList()
    : Continuation(), timeout(0), action(0), mtu(0), blast_proto(ILL_BLAST), list_head(0), cur_len(0)
  {  }

  void init(PrefetchBlastType btype = UDP_BLAST, int tout = 0, int xmtu = INT_MAX) {
    SET_HANDLER((int (BlasterUrlList::*)(int, void *))(&BlasterUrlList::handleEvent));
    mutex = new_ProxyMutex();
    blast_proto = btype;
    timeout = tout;
    mtu = xmtu;
  }

  void free();

  int handleEvent(int event, void *data);
  void invokeUrlBlaster();
};

extern ClassAllocator<BlasterUrlList> blasterUrlListAllocator;

inline void
BlasterUrlList::free()
{
  mutex = NULL;
  blasterUrlListAllocator.free(this);
}

class PrefetchUrlBlaster:public Continuation
{
public:
  typedef int (PrefetchUrlBlaster::*EventHandler) (int, void *);

    PrefetchUrlBlaster()
  : url_head(0), proto(ILL_BLAST), action(0)
  {
  }

  void init(PrefetchUrlEntry * list_head, PrefetchBlastType u_proto = UDP_BLAST);

  void free();

  PrefetchUrlEntry *url_head;
  PrefetchBlastType proto;

  Action *action;

  void writeBuffer(MIOBuffer * buf);

  int udpUrlBlaster(int event, void *data);

};

extern ClassAllocator<PrefetchUrlBlaster> prefetchUrlBlasterAllocator;

void
PrefetchUrlBlaster::init(PrefetchUrlEntry * list_head, PrefetchBlastType u_proto)
{
  /* More clean up necessary... we should not need this class
     XXXXXXXXX */
  mutex = new_ProxyMutex();

  url_head = list_head;
  proto = u_proto;

  MUTEX_LOCK(lock, mutex, this_ethread());

  udpUrlBlaster(SIMPLE_EVENT_EVENTS_START, NULL);
}

inline void
BlasterUrlList::invokeUrlBlaster()
{
  PrefetchUrlBlaster *u_blaster = prefetchUrlBlasterAllocator.alloc();
  u_blaster->init(list_head, blast_proto);
  list_head = NULL;
  cur_len = 0;
}

class PrefetchBlaster:public Continuation
{

public:
  typedef int (PrefetchBlaster::*EventHandler) (int event, void *data);

    PrefetchBlaster()
  : Continuation(), url_ent(0), transform(0), url_list(0), request(0),
    cache_http_info(0), buf(0), reader(0), serverVC(0), data_proto(0), n_pkts_sent(0), seq_no(0), io_block(0)
  {
  };
  ~PrefetchBlaster() {
  };

  int init(PrefetchUrlEntry * entry, HTTPHdr * request, PrefetchTransform * p_trans);

  int handleEvent(int event, void *data);
  int bufferObject(int event, void *data);
  int blastObject(int event, void *data);
  int httpClient(int event, void *data);

  int invokeBlaster();
  void initCacheLookupConfig();

  void handleCookieHeaders(HTTPHdr * req_hdr, HTTPHdr * resp_hdr,
                           const char *domain_start, const char *domain_end,
                           const char *host_start, int host_len, bool no_dot);

  void free();

  PrefetchUrlEntry *url_ent;
  PrefetchTransform *transform;
  BlasterUrlList *url_list;

  HTTPHdr *request;
  CacheHTTPInfo *cache_http_info;

  MIOBuffer *buf;
  IOBufferReader *reader;

  VConnection *serverVC;

  unsigned int data_proto;

  CacheLookupHttpConfig cache_lookup_config;

  //udp related:
  uint32_t n_pkts_sent;
  uint32_t seq_no;
  IOBufferBlock *io_block;
};

extern ClassAllocator<PrefetchBlaster> prefetchBlasterAllocator;

/*Conncetion keep alive*/

#define PRELOAD_HEADER_LEN 12   //this is the new header
//assuming bigendian bit order. does any body have a little endian bit order?
#define PRELOAD_HDR_URL_PROMISE_FLAG (0x40000000)
#define PRELOAD_HDR_RESPONSE_FLAG (0x80000000)
#define PRELOAD_UDP_HEADER_LEN 12
#define PRELOAD_UDP_LAST_PKT_FLAG (0x80000000)
#define PRELOAD_UDP_PKT_NUM_MASK (0x7fffffff)

class KeepAliveConn: public Continuation
{
public:

  KeepAliveConn()
    : Continuation(), ip(0), nbytes_added(0)
  { }

  int init(unsigned int ip, MIOBuffer * buf, IOBufferReader * reader);
  void free();

  int append(IOBufferReader * reader);
  int handleEvent(int event, void *data);

  unsigned int ip;

  MIOBuffer *buf;
  IOBufferReader *reader;

  MIOBuffer *read_buf;

  NetVConnection *childVC;
  VIO *vio;

  KeepAliveConn *next;

  int64_t nbytes_added;
};

class KeepAliveConnTable
{
public:

  KeepAliveConnTable():arr(NULL)
  {
  };

  int init();
  void free();
  static int ip_hash(unsigned int ip);
  int append(unsigned int ip, MIOBuffer * buf, IOBufferReader * reader);

  typedef struct
  {
    KeepAliveConn *conn;
    ProxyMutexPtr mutex;
  } conn_elem;

  conn_elem *arr;
};
extern KeepAliveConnTable *g_conn_table;

class KeepAliveLockHandler: public Continuation
{
  /* Used when we miss the lock for the connection */

public:
  KeepAliveLockHandler()
  :Continuation(), ip(0)
  {
  };

  void init(unsigned int xip, MIOBuffer * xbuf, IOBufferReader * xreader)
  {
    mutex = g_conn_table->arr[KeepAliveConnTable::ip_hash(ip)].mutex;

    ip = xip;
    buf = xbuf;
    reader = xreader;

    SET_HANDLER(&KeepAliveLockHandler::handleEvent);
    this_ethread()->schedule_in(this, HRTIME_MSECONDS(10));
  }

  ~KeepAliveLockHandler() {
    mutex = NULL;
  }

  int handleEvent(int event, void *data);

  unsigned int ip;
  MIOBuffer *buf;
  IOBufferReader *reader;
};


#define TS_ReadConfigInteger            REC_ReadConfigInteger
#define TS_ReadConfigString             REC_ReadConfigString
#define TS_EstablishStaticConfigInteger REC_EstablishStaticConfigInteger
#define TS_RegisterConfigUpdateFunc     REC_RegisterConfigUpdateFunc
#define TS_ReadConfigStringAlloc        REC_ReadConfigStringAlloc
#define TS_ConfigReadInteger            REC_ConfigReadInteger
#define TS_ConfigReadString             REC_ConfigReadString


#endif // PREFETCH

#endif // _PREFETCH_H_