#ifndef _ROSE_COMPRESSION_LSMTABLE_H__
#define _ROSE_COMPRESSION_LSMTABLE_H__

#undef end
#undef begin

#include <set>
#include "lsmIterators.h"

namespace rose {
  /**
     @file

     This file contains worker threads and the end user interface for Rose's
     LSM-tree based table implementation.  The page format is set at compile
     time with a template instantiation.

     @see lsmWorkers.h provides a more general (and dynamically
     dispatched), interface to the underlying primititves
  */

  // Lower total work by perfomrming one merge at higher level
  // for every FUDGE^2 merges at the immediately lower level.
  // (Constrast to R, which controls the ratio of sizes of the trees.)
  static const int FUDGE = 1;

  template<class PAGELAYOUT, class ITERA, class ITERB>
    struct merge_args {
      int worker_id;
      pageid_t(*pageAlloc)(int,void*);
      void *pageAllocState;
      pthread_mutex_t * block_ready_mut;
      pthread_cond_t * in_block_needed_cond;
      pthread_cond_t * out_block_needed_cond;
      pthread_cond_t * in_block_ready_cond;
      pthread_cond_t * out_block_ready_cond;
      bool * still_open;
      pageid_t * my_tree_size;
      pageid_t * out_tree_size;
      pageid_t max_size;
      pageid_t r_i;
      typename ITERA::handle in_process_tree;
      typename ITERB::handle ** in_tree;
      typename ITERA::handle ** out_tree;
    };

  template <class PAGELAYOUT, class ITER>
    pageid_t compressData(int xid, ITER * begin, ITER * end, recordid tree,
			  pageid_t (*pageAlloc)(int,void*),
			  void *pageAllocState, uint64_t *inserted) {
    *inserted = 0;

    if(*begin == *end) {
      return 0;
    }
    pageid_t next_page = pageAlloc(xid,pageAllocState);
    Page *p = loadPage(xid, next_page);
    pageid_t pageCount = 0;

    if(*begin != *end) {
      TlsmAppendPage(xid,tree,toByteArray(begin),pageAlloc,pageAllocState,p->id);
    }
    pageCount++;

    typename PAGELAYOUT::FMT * mc = PAGELAYOUT::initPage(p, &**begin);

    int lastEmpty = 0;

    for(ITER i(*begin); i != *end; ++i) {
      rose::slot_index_t ret = mc->append(xid, *i);

      (*inserted)++;

      if(ret == rose::NOSPACE) {
	p->dirty = 1;
	mc->pack();
	releasePage(p);

	--(*end);
	if(i != *end) {
	  next_page = pageAlloc(xid,pageAllocState);
	  p = loadPage(xid, next_page);

	  mc = PAGELAYOUT::initPage(p, &*i);

	  TlsmAppendPage(xid,tree,toByteArray(&i),pageAlloc,pageAllocState,p->id);

	  pageCount++;
	  lastEmpty = 0;
	} else {
	  lastEmpty = 1;
	}
	++(*end);
	--i;
      }
    }

    p->dirty = 1;
    mc->pack();
    releasePage(p);
    return pageCount;
  }


  /**
     ITERA is an iterator over the data structure that mergeThread creates (a lsm tree iterator).
     ITERB is an iterator over the data structures that mergeThread takes as input (lsm tree, or rb tree..)
  */
  template<class PAGELAYOUT, class ITERA, class ITERB>
    void* mergeThread(void* arg) {
    // The ITER argument of a is unused (we don't look at it's begin or end fields...)
    merge_args<PAGELAYOUT, ITERA, ITERB> * a = (merge_args<PAGELAYOUT, ITERA, ITERB>*)arg;

    struct timeval start_tv, wait_tv, stop_tv;

    int merge_count = 0;

    int xid = Tbegin();

    // Initialize tree with an empty tree.
    // XXX hardcodes ITERA's type:
    typename ITERA::handle oldtree
      = new typename ITERA::treeIteratorHandle(
		TlsmCreate(xid, PAGELAYOUT::cmp_id(),a->pageAlloc,
		  a->pageAllocState,PAGELAYOUT::FMT::TUP::sizeofBytes()) );

    Tcommit(xid);
    // loop around here to produce multiple batches for merge.

    gettimeofday(&start_tv,0);

    while(1) {


      pthread_mutex_lock(a->block_ready_mut);

      int done = 0;

      while(!*(a->in_tree)) {
	pthread_cond_signal(a->in_block_needed_cond);
	if(!*(a->still_open)) {
	  done = 1;
	  break;
	}
	pthread_cond_wait(a->in_block_ready_cond,a->block_ready_mut);
      }
      if(done) {
	a->in_process_tree = oldtree;
	pthread_cond_signal(a->out_block_ready_cond);
	pthread_mutex_unlock(a->block_ready_mut);
	break;
      }

      gettimeofday(&wait_tv,0);

      ITERA taBegin(oldtree);
      ITERB tbBegin(**a->in_tree);

      ITERA *taEnd = taBegin.end();
      ITERB *tbEnd = tbBegin.end();


      pthread_mutex_unlock(a->block_ready_mut);

      xid = Tbegin();

      recordid tree = TlsmCreate(xid, PAGELAYOUT::cmp_id(),a->pageAlloc,
			a->pageAllocState,PAGELAYOUT::FMT::TUP::sizeofBytes());

      mergeIterator<ITERA, ITERB, typename PAGELAYOUT::FMT::TUP>
	mBegin(taBegin, tbBegin, *taEnd, *tbEnd);

      mergeIterator<ITERA, ITERB, typename PAGELAYOUT::FMT::TUP>
	mEnd(taBegin, tbBegin, *taEnd, *tbEnd);

      mEnd.seekEnd();
      uint64_t insertedTuples;

      pageid_t mergedPages = compressData
	<PAGELAYOUT,mergeIterator<ITERA,ITERB,typename PAGELAYOUT::FMT::TUP> >
	(xid, &mBegin, &mEnd,tree,a->pageAlloc,a->pageAllocState,&insertedTuples);

      delete taEnd;
      delete tbEnd;


      gettimeofday(&stop_tv,0);

      // TlsmFree(wait_queue[0])  /// XXX Need to implement (de)allocation!
      // TlsmFree(wait_queue[1])

      merge_count++;

      double wait_elapsed  = tv_to_double(wait_tv) - tv_to_double(start_tv);
      double work_elapsed  = tv_to_double(stop_tv) - tv_to_double(wait_tv);
      double total_elapsed = wait_elapsed + work_elapsed;
      double ratio = ((double)(insertedTuples * (uint64_t)PAGELAYOUT::FMT::TUP::sizeofBytes()))
	/ (double)(PAGE_SIZE * mergedPages);
      double throughput = ((double)(insertedTuples * (uint64_t)PAGELAYOUT::FMT::TUP::sizeofBytes()))
	/ (1024.0 * 1024.0 * total_elapsed);

      printf("worker %d merge # %-6d: comp ratio: %-9.3f  waited %6.1f sec   "
	     "worked %6.1f sec inserts %-12ld (%9.3f mb/s) %6d pages (need %6d)\n", a->worker_id, merge_count, ratio,
	     wait_elapsed, work_elapsed, (unsigned long)insertedTuples, throughput, mergedPages, !a->out_tree_size ? -1 :  (FUDGE * *a->out_tree_size / a->r_i));


      gettimeofday(&start_tv,0);

      pthread_mutex_lock(a->block_ready_mut);

      // keep actual handle around so that it can be freed below.
      typename ITERB::handle old_in_tree = **a->in_tree;
      delete old_in_tree;
      free(*a->in_tree); // free pointer to handle

      // XXX should we delay this to this point?
      //   otherwise, the contents of in_tree become temporarily unavailable to observers.
      *a->in_tree = 0; // tell producer that the slot is now open

      pthread_cond_signal(a->in_block_needed_cond);


      if(a->out_tree_size) {
	*a->my_tree_size = *a->out_tree_size / (a->r_i * FUDGE);
      } else {
	if(*a->my_tree_size < mergedPages) {
	  *a->my_tree_size = mergedPages;
	}
      }

      if(a->out_tree &&  // is there a upstream merger? (note the lack of the * on a->out_tree)
	 ((a->max_size && mergedPages > a->max_size )
	  ||
	  mergedPages > (FUDGE * *a->out_tree_size / a->r_i)) // do we have enough data to bother it?
	 ) {
	while(*a->out_tree) { // we probably don't need the "while..."
	  pthread_cond_wait(a->out_block_needed_cond, a->block_ready_mut);
	}

	// XXX C++?  Objects?  Constructors? Who needs them?
	*a->out_tree = (typeof(*a->out_tree))malloc(sizeof(**a->out_tree));
	**a->out_tree = new typename ITERA::treeIteratorHandle(tree);
	pthread_cond_signal(a->out_block_ready_cond);

	// This is a bit wasteful; allocate a new empty tree to merge against.
	// We don't want to ever look at the one we just handed upstream...
	// We could wait for an in tree to be ready, and then pass it directly
	// to compress data (to avoid all those merging comparisons...)
	tree = TlsmCreate(xid, PAGELAYOUT::cmp_id(),a->pageAlloc,
			a->pageAllocState,PAGELAYOUT::FMT::TUP::sizeofBytes());

      }

      // XXX   TlsmFree(xid,oldtree);

      *oldtree = tree;

      pthread_mutex_unlock(a->block_ready_mut);

      Tcommit(xid);

    }
    return 0;
  }
  typedef struct {
    recordid bigTree;
    recordid bigTreeAllocState; // this is probably the head of an arraylist of regions used by the tree...
    recordid mediumTree;
    recordid mediumTreeAllocState;
    epoch_t beginning;
    epoch_t end;
  } lsmTableHeader_t;


  template<class PAGELAYOUT>
    inline recordid TlsmTableAlloc(int xid) {

    // XXX use a (slow) page allocator in alloc, then create a new
    // (fast) region allocator in start.

    recordid ret = Talloc(xid, sizeof(lsmTableHeader_t));
    lsmTableHeader_t h;
    h.bigTreeAllocState = Talloc(xid,sizeof(TlsmRegionAllocConf_t));
    Tset(xid,h.bigTreeAllocState,&LSM_REGION_ALLOC_STATIC_INITIALIZER);
    h.bigTree = TlsmCreate(xid, PAGELAYOUT::cmp_id(),
			   TlsmRegionAllocRid,&h.bigTreeAllocState,
			   PAGELAYOUT::FMT::TUP::sizeofBytes());
    h.mediumTreeAllocState = Talloc(xid,sizeof(TlsmRegionAllocConf_t));
    Tset(xid,h.mediumTreeAllocState,&LSM_REGION_ALLOC_STATIC_INITIALIZER);
    h.mediumTree = TlsmCreate(xid, PAGELAYOUT::cmp_id(),
			      TlsmRegionAllocRid,&h.mediumTreeAllocState,
			      PAGELAYOUT::FMT::TUP::sizeofBytes());
    epoch_t beginning = 0;
    epoch_t end = 0;
    Tset(xid, ret, &h);
    return ret;
  }

  template <class PAGELAYOUT>
  struct lsmTableHandle {
    pthread_t merge1_thread;
    pthread_t merge2_thread;
    bool * still_open;
    typename stlSetIterator
      <typename std::set
        <typename PAGELAYOUT::FMT::TUP,
         typename PAGELAYOUT::FMT::TUP::stl_cmp>,
       typename PAGELAYOUT::FMT::TUP>::handle ** input_handle;
    typename std::set
      <typename PAGELAYOUT::FMT::TUP,
      typename PAGELAYOUT::FMT::TUP::stl_cmp> * scratch_handle;
    pthread_mutex_t * mut;
    pthread_cond_t * input_ready_cond;
    pthread_cond_t * input_needed_cond;
    pageid_t * input_size;
    merge_args<PAGELAYOUT, treeIterator<typename PAGELAYOUT::FMT::TUP,
      typename PAGELAYOUT::FMT>, treeIterator<typename PAGELAYOUT::FMT::TUP,
      typename PAGELAYOUT::FMT> > * args1;
    merge_args<PAGELAYOUT, treeIterator<typename PAGELAYOUT::FMT::TUP,
      typename PAGELAYOUT::FMT>, stlSetIterator<typename std::set<typename PAGELAYOUT::FMT::TUP,
      typename PAGELAYOUT::FMT::TUP::stl_cmp>,
      typename PAGELAYOUT::FMT::TUP> > * args2;
  };

  // How many bytes of tuples can we afford to keep in RAM?
  // this is just a guessed value... it seems about right based on
  // experiments, but 450 bytes overhead per tuple is insane!
  static const int RB_TREE_OVERHEAD = 450;
  static const pageid_t MEM_SIZE = 800 * 1000 * 1000;
  // How many pages should we try to fill with the first C1 merge?
  static const pageid_t START_SIZE = /*10 **/ 1000;
  static const int R = 10; // XXX set this as low as possible (for dynamic setting.  = sqrt(C2 size / C0 size))

  template<class PAGELAYOUT>
    lsmTableHandle <PAGELAYOUT> * TlsmTableStart(recordid& tree) {
    /// XXX xid for daemon processes?
    lsmTableHeader_t h;
    Tread(-1, tree, &h);

    typedef treeIterator<typename PAGELAYOUT::FMT::TUP,
      typename PAGELAYOUT::FMT> LSM_ITER;

    typedef stlSetIterator<typename std::set<typename PAGELAYOUT::FMT::TUP,
      typename PAGELAYOUT::FMT::TUP::stl_cmp>,
      typename PAGELAYOUT::FMT::TUP> RB_ITER;

    typedef typename LSM_ITER::handle LSM_HANDLE;
    typedef typename RB_ITER::handle RB_HANDLE;

    pthread_mutex_t * block_ready_mut =
      (pthread_mutex_t*)malloc(sizeof(pthread_mutex_t));
    pthread_cond_t  * block0_needed_cond =
      (pthread_cond_t*)malloc(sizeof(pthread_cond_t));
    pthread_cond_t  * block1_needed_cond =
      (pthread_cond_t*)malloc(sizeof(pthread_cond_t));
    pthread_cond_t  * block2_needed_cond =
      (pthread_cond_t*)malloc(sizeof(pthread_cond_t));
    pthread_cond_t  * block0_ready_cond =
      (pthread_cond_t*)malloc(sizeof(pthread_cond_t));
    pthread_cond_t  * block1_ready_cond =
      (pthread_cond_t*)malloc(sizeof(pthread_cond_t));
    pthread_cond_t  * block2_ready_cond =
      (pthread_cond_t*)malloc(sizeof(pthread_cond_t));

    pthread_mutex_init(block_ready_mut,0);
    pthread_cond_init(block0_needed_cond,0);
    pthread_cond_init(block1_needed_cond,0);
    pthread_cond_init(block2_needed_cond,0);
    pthread_cond_init(block0_ready_cond,0);
    pthread_cond_init(block1_ready_cond,0);
    pthread_cond_init(block2_ready_cond,0);

    pageid_t * block0_size = (pageid_t*)malloc(sizeof(pageid_t));
    // don't merge until we have enough data to be worthwhile...
    *block0_size = START_SIZE;
    pageid_t * block1_size = (pageid_t*)malloc(sizeof(pageid_t));
    // similarly, wait to merge the next block until we have merged block FUDGE times.
    *block1_size = FUDGE * R * *block0_size;

    LSM_HANDLE ** block1_scratch = (LSM_HANDLE**) malloc(sizeof(LSM_HANDLE*));
    *block1_scratch = 0;

    RB_HANDLE ** block0_scratch = (RB_HANDLE**) malloc(sizeof(RB_HANDLE*));
    *block0_scratch = 0;

    lsmTableHandle<PAGELAYOUT> * ret = (lsmTableHandle<PAGELAYOUT>*)
      malloc(sizeof(lsmTableHandle<PAGELAYOUT>));

    // merge1_thread initialized during pthread_create, below.
    // merge2_thread initialized during pthread_create, below.

    ret->still_open = (bool*)malloc(sizeof(bool));
    *ret->still_open = 1;

    ret->input_handle = block0_scratch;
    ret->scratch_handle = new typeof(*ret->scratch_handle);

    ret->mut = block_ready_mut;

    ret->input_ready_cond = block0_ready_cond;
    ret->input_needed_cond = block0_needed_cond;
    ret->input_size = block0_size;

    recordid * ridp = (recordid*)malloc(sizeof(recordid));
    *ridp = h.bigTreeAllocState;

    ret->args1 = (merge_args<PAGELAYOUT,LSM_ITER,LSM_ITER>*)malloc(sizeof(merge_args<PAGELAYOUT,LSM_ITER,LSM_ITER>));
    merge_args<PAGELAYOUT, LSM_ITER, LSM_ITER> tmpargs1 =
      {
	1,
	TlsmRegionAllocRid,
	ridp,
	block_ready_mut,
	block1_needed_cond,
	block2_needed_cond,
	block1_ready_cond,
	block2_ready_cond,
	ret->still_open,
	block1_size,
	0, // biggest component computes its size directly.
	0, // No max size for biggest component
	R,
	new typename LSM_ITER::treeIteratorHandle(NULLRID),
	block1_scratch,
	0
      };
    *ret->args1 = tmpargs1;
    void * (*merger1)(void*) = mergeThread<PAGELAYOUT, LSM_ITER, LSM_ITER>;

    ridp = (recordid*)malloc(sizeof(recordid));
    *ridp = h.mediumTreeAllocState;

    ret->args2 = (merge_args<PAGELAYOUT,LSM_ITER,RB_ITER>*)malloc(sizeof(merge_args<PAGELAYOUT,LSM_ITER,RB_ITER>));
    merge_args<PAGELAYOUT, LSM_ITER, RB_ITER> tmpargs2 =
      {
	2,
	TlsmRegionAllocRid,
	ridp,
	block_ready_mut,
	block0_needed_cond,
	block1_needed_cond,
	block0_ready_cond,
	block1_ready_cond,
	ret->still_open,
	block0_size,
	block1_size,
	(R * MEM_SIZE) / (PAGE_SIZE * 4),  // XXX 4 = estimated compression ratio
	R,
	new typename LSM_ITER::treeIteratorHandle(NULLRID),
	block0_scratch,
	block1_scratch
      };
    *ret->args2 = tmpargs2;
    void * (*merger2)(void*) = mergeThread<PAGELAYOUT, LSM_ITER, RB_ITER>;

    pthread_create(&ret->merge1_thread, 0, merger1, ret->args1);
    pthread_create(&ret->merge2_thread, 0, merger2, ret->args2);

    return ret;
  }
  template<class PAGELAYOUT>
    void TlsmTableFlush(lsmTableHandle<PAGELAYOUT> *h) {
      pthread_mutex_lock(h->mut);

      while(*h->input_handle) {
	pthread_cond_wait(h->input_needed_cond, h->mut);
      }

      typeof(h->scratch_handle)* tmp_ptr
	= (typeof(h->scratch_handle)*) malloc(sizeof(void*));
      *tmp_ptr = h->scratch_handle;
      *(h->input_handle) = tmp_ptr;

      pthread_cond_signal(h->input_ready_cond);
      h->scratch_handle = new typeof(*h->scratch_handle);

      pthread_mutex_unlock(h->mut);

  }
  template<class PAGELAYOUT>
    void TlsmTableStop( lsmTableHandle<PAGELAYOUT> * h) {
    TlsmTableFlush(h);
    *(h->still_open) = 0;
    pthread_join(h->merge1_thread,0);
    pthread_join(h->merge2_thread,0);
  }
  template<class PAGELAYOUT>
    void TlsmTableInsert( lsmTableHandle<PAGELAYOUT> *h,
			  typename PAGELAYOUT::FMT::TUP &t) {
    h->scratch_handle->insert(t);
    //XXX  4 = estimated compression ratio.

    uint64_t handleBytes = h->scratch_handle->size() * (RB_TREE_OVERHEAD + PAGELAYOUT::FMT::TUP::sizeofBytes());
    uint64_t inputSizeThresh = (4 * PAGE_SIZE * *h->input_size); // / (PAGELAYOUT::FMT::TUP::sizeofBytes());
    uint64_t memSizeThresh = MEM_SIZE;

    if(handleBytes > inputSizeThresh || handleBytes > memSizeThresh) { // XXX ok?
      printf("Handle mbytes %ld Input size: %ld input size thresh: %ld mbytes mem size thresh: %ld\n",
	     handleBytes / (1024*1024), *h->input_size, inputSizeThresh / (1024*1024), memSizeThresh / (1024*1024));
      TlsmTableFlush<PAGELAYOUT>(h);
    }

  }
}

#endif  // _ROSE_COMPRESSION_LSMTABLE_H__