gecko-dev/dom/plugins/base/nsPluginsDirUtils.h

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsPluginsDirUtils_h___
#define nsPluginsDirUtils_h___

#include "nsPluginsDir.h"
#include "nsTArray.h"
#include "prmem.h"

///////////////////////////////////////////////////////////////////////////////
// Output format from NPP_GetMIMEDescription: "...mime type[;version]:[extension]:[desecription];..."
// The ambiguity of mime description could cause the browser fail to parse the MIME types 
// correctly.
// E.g. "mime type::desecription;" // correct w/o ext 
//      "mime type:desecription;"  // wrong w/o ext 
//
static nsresult
ParsePluginMimeDescription(const char *mdesc, nsPluginInfo &info)
{
    nsresult rv = NS_ERROR_FAILURE;
    if (!mdesc || !*mdesc)
       return rv;

    char *mdescDup = PL_strdup(mdesc); // make a dup of intput string we'll change it content
    char anEmptyString[] = "";
    AutoTArray<char*, 8> tmpMimeTypeArr;
    char delimiters[] = {':',':',';'};
    int mimeTypeVariantCount = 0;
    char *p = mdescDup; // make a dup of intput string we'll change it content
    while(p) {
        char *ptrMimeArray[] = {anEmptyString, anEmptyString, anEmptyString};

        // It's easy to point out ptrMimeArray[0] to the string sounds like
        // "Mime type is not specified, plugin will not function properly."
        // and show this on "about:plugins" page, but we have to mark this particular
        // mime type of given plugin as disable on "about:plugins" page,
        // which feature is not implemented yet.
        // So we'll ignore, without any warnings, an empty description strings, 
        // in other words, if after parsing ptrMimeArray[0] == anEmptyString is true.
        // It is possible do not to registry a plugin at all if it returns
        // an empty string on GetMIMEDescription() call,
        // e.g. plugger returns "" if pluggerrc file is not found.

        char *s = p;
        int i;
        for (i = 0; i < (int) sizeof(delimiters) && (p = PL_strchr(s, delimiters[i])); i++) {
            ptrMimeArray[i] = s; // save start ptr
            *p++ = 0; // overwrite delimiter
            s = p; // move forward
        }
        if (i == 2)
           ptrMimeArray[i] = s;
        // fill out the temp array 
        // the order is important, it should be the same in for loop below 
        if (ptrMimeArray[0] != anEmptyString) {
            tmpMimeTypeArr.AppendElement(ptrMimeArray[0]);
            tmpMimeTypeArr.AppendElement(ptrMimeArray[1]);
            tmpMimeTypeArr.AppendElement(ptrMimeArray[2]);
            mimeTypeVariantCount++;
        }
    }

    // fill out info structure
    if (mimeTypeVariantCount) {
        info.fVariantCount         = mimeTypeVariantCount;
        // we can do these 3 mallocs at once, later on code cleanup
        info.fMimeTypeArray        = (char **)PR_Malloc(mimeTypeVariantCount * sizeof(char *));
        info.fMimeDescriptionArray = (char **)PR_Malloc(mimeTypeVariantCount * sizeof(char *));
        info.fExtensionArray       = (char **)PR_Malloc(mimeTypeVariantCount * sizeof(char *));

        int j,i;
        for (j = i = 0; i < mimeTypeVariantCount; i++) {
            // the order is important, do not change it
           // we can get rid of PL_strdup here, later on code cleanup
            info.fMimeTypeArray[i]        =  PL_strdup(tmpMimeTypeArr.ElementAt(j++));
            info.fExtensionArray[i]       =  PL_strdup(tmpMimeTypeArr.ElementAt(j++));
            info.fMimeDescriptionArray[i] =  PL_strdup(tmpMimeTypeArr.ElementAt(j++));
        }
        rv = NS_OK;
    }
    if (mdescDup)
        PR_Free(mdescDup);
    return rv;
}

#endif /* nsPluginsDirUtils_h___ */