poppler/NameToCharCode.cc

//========================================================================
//
// NameToCharCode.cc
//
// Copyright 2001-2003 Glyph & Cog, LLC
//
//========================================================================

//========================================================================
//
// Modified under the Poppler project - http://poppler.freedesktop.org
//
// All changes made under the Poppler project to this file are licensed
// under GPL version 2 or later
//
// Copyright (C) 2019 Albert Astals Cid <aacid@kde.org>
//
// To see a description of the changes please see the Changelog file that
// came with your tarball or type make ChangeLog if you are building from git
//
//========================================================================

#include <config.h>

#include <cstring>
#include "goo/gmem.h"
#include "NameToCharCode.h"

//------------------------------------------------------------------------

struct NameToCharCodeEntry
{
    char *name;
    CharCode c;
};

//------------------------------------------------------------------------

NameToCharCode::NameToCharCode()
{
    int i;

    size = 31;
    len = 0;
    tab = (NameToCharCodeEntry *)gmallocn(size, sizeof(NameToCharCodeEntry));
    for (i = 0; i < size; ++i) {
        tab[i].name = nullptr;
    }
}

NameToCharCode::~NameToCharCode()
{
    int i;

    for (i = 0; i < size; ++i) {
        if (tab[i].name) {
            gfree(tab[i].name);
        }
    }
    gfree(tab);
}

void NameToCharCode::add(const char *name, CharCode c)
{
    NameToCharCodeEntry *oldTab;
    int h, i, oldSize;

    // expand the table if necessary
    if (len >= size / 2) {
        oldSize = size;
        oldTab = tab;
        size = 2 * size + 1;
        tab = (NameToCharCodeEntry *)gmallocn(size, sizeof(NameToCharCodeEntry));
        for (h = 0; h < size; ++h) {
            tab[h].name = nullptr;
        }
        for (i = 0; i < oldSize; ++i) {
            if (oldTab[i].name) {
                h = hash(oldTab[i].name);
                while (tab[h].name) {
                    if (++h == size) {
                        h = 0;
                    }
                }
                tab[h] = oldTab[i];
            }
        }
        gfree(oldTab);
    }

    // add the new name
    h = hash(name);
    while (tab[h].name && (strcmp(tab[h].name, name) != 0)) {
        if (++h == size) {
            h = 0;
        }
    }
    if (!tab[h].name) {
        tab[h].name = copyString(name);
    }
    tab[h].c = c;

    ++len;
}

CharCode NameToCharCode::lookup(const char *name) const
{
    int h;

    h = hash(name);
    while (tab[h].name) {
        if (!strcmp(tab[h].name, name)) {
            return tab[h].c;
        }
        if (++h == size) {
            h = 0;
        }
    }
    return 0;
}

int NameToCharCode::hash(const char *name) const
{
    const char *p;
    unsigned int h;

    h = 0;
    for (p = name; *p; ++p) {
        h = 17 * h + (int)(*p & 0xff);
    }
    return (int)(h % size);
}