BBS: Inland Empire Archive
Date: 04-11-92 (17:14) Number: 10
From: JEAN CREPEAU Refer#: NONE
To: ASA ROSSOFF Recvd: NO
Subj: Fast Indexing....? Conf: (2) Quik_Bas
In a message to ALL, ASA ROSSOFF wrote:
AR=> I wrote a program to display quotes from a file.... But it's very slow
the first time it's run, because it creates an index file... I see
programs written in other languages creating similar index files in
seconds, while my program takes about 20 minutes.... (for a 360k quote
file)
AR=> The index file is about 14k for a 360k file...
AR=> Here's my code to create the index file... any ideas or suggestions
would be GREATLY appreciated...
AR=> COOKIE.TXT is simply a text file, and a blank line designates the
beginning of a new cookie...
I understand why it's so long. You read your text file on a
character basis... Use the following sub instead. It recreates your text
files by eliminating blank lines. This subroutine takes the input file, and
creates to new files (filename.DAT and filename.REF). You should not name
your input file with the .DAT or .REF extension.
DEFLNG A-Z
SUB MAKEINDEX(INFILE$)
I=INSTR(INFILE$,"."):IF I THEN F2$=LEFT$(INFILE$,I-1) ELSE F2$=INFILE$
F1$=F2$+".DAT"
F2$=F2$+".REF"
OPEN INFILE$ FOR INPUT ACCESS READ LOCK WRITE AS #1
OPEN F1$ FOR OUTPUT ACCESS WRITE LOCK READ WRITE AS #2
OPEN F2$ FOR BINARY ACCESS WRITE LOCK READ WRITE AS #3
U$=""
WHILE NOT EOF(1)
IF LEN(U$)>8192 THEN
PUT #3,,U$
U$=""
ENDIF
LINE INPUT #1,X$
IF LEN(X$) THEN
U$=U$+MKL$(LOF(2)+1)
PRINT #2,X$
ENDIF
WEND
PUT #3,,U$
CLOSE
END SUB
The file #3 is buffered with u$, which is an 8K buffer. The sub
runs faster this way.
OPEN "FILENAME.DAT" FOR INPUT ACCESS READ LOCK WRITE AS #2
OPEN "FILENAME.REF" ACCESS READ LOCK WRITE AS #3 LEN=4
DIM idx AS LONG
ntot=LOF(3)/4 gives the number of quotes in your file
GET #3,n,idx These 3 lines give you the nth quote in your file
SEEK #2,idx 1 <= n <= ntot
LINE INPUT #2,x$ x$ = quote
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* Origin: INTERACESS Montreal (QC) Canada (514) 528-1415 (1:167/280)
