/* * Example 6: BTree-on-disk. Retrieves birthdays, given a name * * $Id: btreedsk.cpp,v 7.6 1996/09/30 17:15:45 griswolf Exp $ * * Copyright (c) 1989-1999 Rogue Wave Software, Inc. All Rights Reserved. * * This computer software is owned by Rogue Wave Software, Inc. and is * protected by U.S. copyright laws and other laws and by international * treaties. This computer software is furnished by Rogue Wave Software, * Inc. pursuant to a written license agreement and may be used, copied, * transmitted, and stored only in accordance with the terms of such * license and with the inclusion of the above copyright notice. This * computer software or any other copies thereof may not be provided or * otherwise made available to any other person. * * U.S. Government Restricted Rights. This computer software is provided * with Restricted Rights. Use, duplication, or disclosure by the * Government is subject to restrictions as set forth in subparagraph (c) * (1) (ii) of The Rights in Technical Data and Computer Software clause * at DFARS 252.227-7013 or subparagraphs (c) (1) and (2) of the * Commercial Computer Software – Restricted Rights at 48 CFR 52.227-19, * as applicable. Manufacturer is Rogue Wave Software, Inc., 5500 * Flatiron Parkway, Boulder, Colorado 80301 USA. * *************************************************************************** */ #include "rw/disktree.h" #include "rw/filemgr.h" #include "rw/rwdate.h" #include "rw/cstring.h" #include "rw/rstream.h" /* The following hack is made necessary by a bug in the DLL implementation * Microsoft's V4.2 Standard Library */ #ifdef RW_MSVC_DLL_LOCALE_FACET # define VC42_FORCE_CLOCALE(z) \ locale *_temploc=(z.getloc()==locale("C"))?&(z.imbue(locale::classic())):0; # define VC42_REPLACE_LOCALE(z) \ if ( _temploc ) z.imbue(*_temploc); #else # define VC42_FORCE_CLOCALE(z) # define VC42_REPLACE_LOCALE(z) #endif #ifdef applec # define RW_END_PROMPT endl << flush #else # define RW_END_PROMPT flush #endif // example of using a struct for the void* in applyToKeyAndValue: struct printStruct { RWFileManager* filemgr; unsigned keyLen; }; // Function to print a key and value: void printKey(const char* a, RWstoredValue sv, void* x); // prototype void printKey(const char* a, RWstoredValue sv, void* x) { /* * If we're using the Standard C++ Library and the iostream operators * are in the std namespace, we need to pull in namespace std, or * scope the operator with std::. */ #if !defined(RW_NO_STL) && !defined(RW_NO_STD_NAMESPACE) && !defined(RW_NO_IOSTD) using namespace std; #endif /* * borland 4 needs the std namespace */ #if defined(RW_BCB_NAMESPACE) using namespace std; #endif printStruct *ps = (struct printStruct *)x; unsigned len = ps->keyLen; RWCString key(a,len); // don\'t count on trailing \0 in key RWDate bday; RWFileManager* fm = ps->filemgr; fm->SeekTo(sv); bday.restoreFrom(*fm); cout << "Name: " << key << " birthday: " << bday << endl; } int main() { #if !defined(RW_NO_STL) && !defined(RW_NO_STD_NAMESPACE) && !defined(RW_NO_IOSTD) using namespace std; #endif /* * borland 4 needs the std namespace */ #if defined(RW_BCB_NAMESPACE) using namespace std; #endif RWCString filename; RWDate birthday; RWoffset loc; cout << " RWBTreeOnDisk sample program.\n"; cout << " Stores names and birthdays in a BTree.\n"; cout << "Enter either the name of a new file or of a pre-existing file: " << RW_END_PROMPT; filename.readLine(cin); RWFileManager fmgr(filename.data()); RWBTreeOnDisk bt(fmgr); // Construct a B Tree with allocations managed by fmgr // display a list of this tree's parameters cout << "The RWBTreeOnDisk being managed in file " << filename; cout << ", has: " << endl; cout << "\tCache blocks:\t" << bt.cacheCount() << endl; cout << "\tVersion:\t0x" << hex << bt.version() << dec << endl; cout << "\tKey Length:\t" << bt.keyLength() << endl; cout << "\tOrder:\t\t" << bt.order() << endl; cout << "\tMinimum Order:\t" << bt.minOrder() << endl; cout << "\tHeight:\t\t" << bt.height() << endl; cout << "\tEntries:\t" << bt.entries() << endl; cout << endl; // Loop to do various things to the tree: char response; while (1) { cout << "(i)ns (n)umber of entries (f)ind (d)el (l)ist (c)lear e(x)it: " << RW_END_PROMPT; /* * Read the character; check for EOF. */ VC42_FORCE_CLOCALE(cin); if ( !(cin >> response).good() || response=='x' || response=='X') break; VC42_REPLACE_LOCALE(cin); RWCString name; RWCString retKey; switch ( response ) { // Insert a key-value pair. case 'i': case 'I': cout << "Person's name: " << RW_END_PROMPT; // Prompt cin >> ws; // Skip any leading whitespace name.readLine(cin); // Get the person's name. name.resize(bt.keyLength()); // Trim to the size of the B-Tree key. cout << "Birthday: " << RW_END_PROMPT; // Prompt for the person's birthday. cin >> birthday; // Read it in if( birthday.isValid() ) // Check validity { loc = fmgr.allocate(birthday.binaryStoreSize()); fmgr.SeekTo(loc); birthday.saveOn(fmgr); bt.insertKeyAndValue(name.data(), loc); // Remember the location. } else { cin.clear(); // Clear state cout << "Bad date.\n"; } break; // Find a person's birthday: case 'f': case 'F': cout << "Person's name: " << RW_END_PROMPT; // Prompt cin >> ws; // Skip leading whitespace name.readLine(cin); // Get the person's name, to use as the key. name.resize(bt.keyLength()); // Trim to the size of the B-Tree key. // Go find the birthday location. if(! bt.findKeyAndValue(name.data(), retKey, loc)) cout << name << " not found.\n"; else { fmgr.SeekTo(loc); birthday.restoreFrom(fmgr); // Retrieve the birthday. cout << "Birthday is " << birthday << endl; } break; // Delete a person: case 'd': case 'D': cout << "Name of person to delete: " << RW_END_PROMPT; cin >> ws; name.readLine(cin); name.resize(bt.keyLength()); if(! bt.removeKeyAndValue(name.data(),loc)) cout << "Can't find " << name << " to delete" << endl; else fmgr.deallocate(loc); break; // List the number of entries: case 'n': case 'N': cout << "Number of items in tree: " << bt.entries() << endl; break; // Clear the tree: case 'c': case 'C': cout << "Clearing..." << flush; bt.clear(); // Remove all keys. cout << "done.\n" << flush; break; // Print all entries: case 'l': struct printStruct ps; ps.filemgr = &fmgr; ps.keyLen = bt.keyLength(); bt.applyToKeyAndValue(printKey, &ps); break; default: cerr << "Input not recognized...try again\n"; } // end switch } return 0; }