//  Judy arrays 13 DEC 2012 (judy64n.c from http://code.google.com/p/judyarray/ )
//  This code is public domain.

//  Author Karl Malbrain, malbrain AT yahoo.com
//  with assistance from Jan Weiss.
//  modifications (and any bugs) by Mark Pictor, mpictor at gmail

//  Simplified judy arrays for strings and integers
//  Adapted from the ideas of Douglas Baskins of HP.

//  Map a set of keys to corresponding memory cells (uints).
//  Each cell must be set to a non-zero value by the caller.

//  STANDALONE is defined to compile into a string sorter.

//  String mappings are denoted by calling judy_open with zero as
//  the second argument.  Integer mappings are denoted by calling
//  judy_open with the Integer depth of the Judy Trie as the second
//  argument.

#include "judy.h"
#include "sort.h"

//    memory map input file and sort

//    define pennysort parameters
unsigned int PennyRecs = ( 4096 * 400 );  // records to sort to temp files
unsigned int PennyLine = 100;            // length of input record
unsigned int PennyKey = 10;                // length of input key
unsigned int PennyOff = 0;                // key offset in input record

unsigned long long PennyMerge;    // PennyRecs * PennyLine = file map length
unsigned int PennyPasses;                // number of intermediate files created
unsigned int PennySortTime;                // cpu time to run sort
unsigned int PennyMergeTime;            // cpu time to run merge

void sort( FILE * infile, char * outname ) {
    unsigned long long size, off, offset, part;
    int ifd = fileno( infile );
    char filename[512];
    PennySort * line;
    JudySlot * cell;
    unsigned char * inbuff;
    void * judy;
    FILE * out;
#if defined(_WIN32)
    HANDLE hndl, fm;
    DWORD hiword;
    FILETIME dummy[1];
    FILETIME user[1];
#else
    struct tms buff[1];
#endif
    time_t start = time( NULL );

    if( PennyOff + PennyKey > PennyLine ) {
        fprintf( stderr, "Key Offset + Key Length > Record Length\n" ), exit( 1 );
    }

    offset = 0;
    PennyPasses = 0;

#if defined(_WIN32)
    hndl = ( HANDLE )_get_osfhandle( ifd );
    size = GetFileSize( hndl, &hiword );
    fm = CreateFileMapping( hndl, NULL, PAGE_READONLY, hiword, ( DWORD )size, NULL );
    if( !fm ) {
        fprintf( stderr, "CreateFileMapping error %d\n", GetLastError() ), exit( 1 );
    }
    size |= ( unsigned long long )hiword << 32;
#else
    size = lseek( ifd, 0L, 2 );
#endif

    while( offset < size ) {
#if defined(_WIN32)
        part = offset + PennyMerge > size ? size - offset : PennyMerge;
        inbuff = MapViewOfFile( fm, FILE_MAP_READ, offset >> 32, offset, part );
        if( !inbuff ) {
            fprintf( stderr, "MapViewOfFile error %d\n", GetLastError() ), exit( 1 );
        }
#else
        inbuff = mmap( NULL, PennyMerge, PROT_READ,  MAP_SHARED, ifd, offset );

        if( inbuff == MAP_FAILED ) {
            fprintf( stderr, "mmap error %d\n", errno ), exit( 1 );
        }

        if( madvise( inbuff, PennyMerge, MADV_WILLNEED | MADV_SEQUENTIAL ) < 0 ) {
            fprintf( stderr, "madvise error %d\n", errno );
        }
#endif
        judy = judy_open( PennyKey, 0 );

        off = 0;

        //    build judy array from mapped input chunk

        while( offset + off < size && off < PennyMerge ) {
            line = judy_data( judy, sizeof( PennySort ) );
            cell = judy_cell( judy, inbuff + off + PennyOff, PennyKey );
            line->next = *( void ** )cell;
            line->buff = inbuff + off;

            *( PennySort ** )cell = line;
            off += PennyLine;
        }

        sprintf( filename, "%s.%d", outname, PennyPasses );
        out = fopen( filename, "wb" );
        setvbuf( out, NULL, _IOFBF, 4096 * 1024 );

#ifndef _WIN32
        if( madvise( inbuff, PennyMerge, MADV_WILLNEED | MADV_RANDOM ) < 0 ) {
            fprintf( stderr, "madvise error %d\n", errno );
        }
#endif

        //    write judy array in sorted order to temporary file

        cell = judy_strt( judy, NULL, 0 );

        if( cell ) do {
                line = *( PennySort ** )cell;
                do {
                    fwrite( line->buff, PennyLine, 1, out );
                } while( line = line->next );
            } while( cell = judy_nxt( judy ) );

#if defined(_WIN32)
        UnmapViewOfFile( inbuff );
#else
        munmap( inbuff, PennyMerge );
#endif
        judy_close( judy );
        offset += off;
        fflush( out );
        fclose( out );
        PennyPasses++;
    }
    fprintf( stderr, "End Sort %llu secs", ( unsigned long long ) time( NULL ) - start );
#if defined(_WIN32)
    CloseHandle( fm );
    GetProcessTimes( GetCurrentProcess(), dummy, dummy, dummy, user );
    PennySortTime = *( unsigned long long * )user / 10000000;
#else
    times( buff );
    PennySortTime = buff->tms_utime / 100;
#endif
    fprintf( stderr, " Cpu %d\n", PennySortTime );
}

int merge( FILE * out, char * outname ) {
    time_t start = time( NULL );
    char filename[512];
    JudySlot * cell;
    unsigned int nxt, idx;
    unsigned char ** line;
    unsigned int * next;
    void * judy;
    FILE ** in;

    next = calloc( PennyPasses + 1, sizeof( unsigned int ) );
    line = calloc( PennyPasses, sizeof( void * ) );
    in = calloc( PennyPasses, sizeof( void * ) );

    judy = judy_open( PennyKey, 0 );

    // initialize merge with one record from each temp file

    for( idx = 0; idx < PennyPasses; idx++ ) {
        sprintf( filename, "%s.%d", outname, idx );
        in[idx] = fopen( filename, "rb" );
        line[idx] = malloc( PennyLine );
        setvbuf( in[idx], NULL, _IOFBF, 4096 * 1024 );
        fread( line[idx], PennyLine, 1, in[idx] );
        cell = judy_cell( judy, line[idx] + PennyOff, PennyKey );
        next[idx + 1] = *( unsigned int * )cell;
        *cell = idx + 1;
    }

    //    output records, replacing smallest each time

    while( cell = judy_strt( judy, NULL, 0 ) ) {
        nxt = *( unsigned int * )cell;
        judy_del( judy );

        // process duplicates

        while( idx = nxt ) {
            nxt = next[idx--];
            fwrite( line[idx], PennyLine, 1, out );

            if( fread( line[idx], PennyLine, 1, in[idx] ) ) {
                cell = judy_cell( judy, line[idx] + PennyOff, PennyKey );
                next[idx + 1] = *( unsigned int * )cell;
                *cell = idx + 1;
            } else {
                next[idx + 1] = 0;
            }
        }
    }

    for( idx = 0; idx < PennyPasses; idx++ ) {
        fclose( in[idx] );
        free( line[idx] );
    }

    free( line );
    free( next );
    free( in );

    fprintf( stderr, "End Merge %llu secs", ( unsigned long long ) time( NULL ) - start );
#ifdef _WIN32
    {
        FILETIME dummy[1];
        FILETIME user[1];
        GetProcessTimes( GetCurrentProcess(), dummy, dummy, dummy, user );
        PennyMergeTime = *( unsigned long long * )user / 10000000;
    }
#else
    {
        struct tms buff[1];
        times( buff );
        PennyMergeTime = buff->tms_utime / 100;
    }
#endif
    fprintf( stderr, " Cpu %d\n", PennyMergeTime - PennySortTime );
    judy_close( judy );
    fflush( out );
    fclose( out );
    return 0;
}