dir.c

早期freebsd实现

		Hash_SetValue(entry, stb.st_mtime);
		nearmisses += 1;
		return (file);
	    } else {
		free (file);
	    }
	}
	
	if (DEBUG(DIR)) {
	    printf("failed. ");
	}
	Lst_Close (path);

	if (checkedDot) {
	    /*
	     * Already checked by the given name, since . was in the path,
	     * so no point in proceeding...
	     */
	    if (DEBUG(DIR)) {
		printf("Checked . already, returning NULL\n");
	    }
	    return(NULL);
	}
    }
    
    /*
     * Didn't find it that way, either. Sigh. Phase 3. Add its directory
     * onto the search path in any case, just in case, then look for the
     * thing in the hash table. If we find it, grand. We return a new
     * copy of the name. Otherwise we sadly return a NULL pointer. Sigh.
     * Note that if the directory holding the file doesn't exist, this will
     * do an extra search of the final directory on the path. Unless something
     * weird happens, this search won't succeed and life will be groovy.
     *
     * Sigh. We cannot add the directory onto the search path because
     * of this amusing case:
     * $(INSTALLDIR)/$(FILE): $(FILE)
     *
     * $(FILE) exists in $(INSTALLDIR) but not in the current one.
     * When searching for $(FILE), we will find it in $(INSTALLDIR)
     * b/c we added it here. This is not good...
     */
#ifdef notdef
    cp[-1] = '\0';
    Dir_AddDir (path, name);
    cp[-1] = '/';
    
    bigmisses += 1;
    ln = Lst_Last (path);
    if (ln == NILLNODE) {
	return ((char *) NULL);
    } else {
	p = (Path *) Lst_Datum (ln);
    }
    
    if (Hash_FindEntry (&p->files, cp) != (Hash_Entry *)NULL) {
	return (strdup (name));
    } else {
	return ((char *) NULL);
    }
#else /* !notdef */
    if (DEBUG(DIR)) {
	printf("Looking for \"%s\"...", name);
    }
    
    bigmisses += 1;
    entry = Hash_FindEntry(&mtimes, name);
    if (entry != (Hash_Entry *)NULL) {
	if (DEBUG(DIR)) {
	    printf("got it (in mtime cache)\n");
	}
	return(strdup(name));
    } else if (stat (name, &stb) == 0) {
	entry = Hash_CreateEntry(&mtimes, name, (Boolean *)NULL);
	if (DEBUG(DIR)) {
	    printf("Caching %s for %s\n", Targ_FmtTime(stb.st_mtime),
		    name);
	}
	Hash_SetValue(entry, stb.st_mtime);
	return (strdup (name));
    } else {
	if (DEBUG(DIR)) {
	    printf("failed. Returning NULL\n");
	}
	return ((char *)NULL);
    }
#endif /* notdef */
}

/*-
 *-----------------------------------------------------------------------
 * Dir_MTime  --
 *	Find the modification time of the file described by gn along the
 *	search path dirSearchPath.
 * 
 * Results:
 *	The modification time or 0 if it doesn't exist
 *
 * Side Effects:
 *	The modification time is placed in the node's mtime slot.
 *	If the node didn't have a path entry before, and Dir_FindFile
 *	found one for it, the full name is placed in the path slot.
 *-----------------------------------------------------------------------
 */
int
Dir_MTime (gn)
    GNode         *gn;	      /* the file whose modification time is
			       * desired */
{
    char          *fullName;  /* the full pathname of name */
    struct stat	  stb;	      /* buffer for finding the mod time */
    Hash_Entry	  *entry;
    
    if (gn->type & OP_ARCHV) {
	return Arch_MTime (gn);
    } else if (gn->path == (char *)NULL) {
	fullName = Dir_FindFile (gn->name, dirSearchPath);
    } else {
	fullName = gn->path;
    }
    
    if (fullName == (char *)NULL) {
	fullName = gn->name;
    }

    entry = Hash_FindEntry(&mtimes, fullName);
    if (entry != (Hash_Entry *)NULL) {
	/*
	 * Only do this once -- the second time folks are checking to
	 * see if the file was actually updated, so we need to actually go
	 * to the file system.
	 */
	if (DEBUG(DIR)) {
	    printf("Using cached time %s for %s\n",
		    Targ_FmtTime((time_t) Hash_GetValue(entry)), fullName);
	}
	stb.st_mtime = (time_t)Hash_GetValue(entry);
	Hash_DeleteEntry(&mtimes, entry);
    } else if (stat (fullName, &stb) < 0) {
	if (gn->type & OP_MEMBER) {
	    return Arch_MemMTime (gn);
	} else {
	    stb.st_mtime = 0;
	}
    }
    if (fullName && gn->path == (char *)NULL) {
	gn->path = fullName;
    }
    
    gn->mtime = stb.st_mtime;
    return (gn->mtime);
}

/*-
 *-----------------------------------------------------------------------
 * Dir_AddDir --
 *	Add the given name to the end of the given path. The order of
 *	the arguments is backwards so ParseDoDependency can do a
 *	Lst_ForEach of its list of paths...
 *
 * Results:
 *	none
 *
 * Side Effects:
 *	A structure is added to the list and the directory is 
 *	read and hashed.
 *-----------------------------------------------------------------------
 */
void
Dir_AddDir (path, name)
    Lst           path;	      /* the path to which the directory should be
			       * added */
    char          *name;      /* the name of the directory to add */
{
    LstNode       ln;	      /* node in case Path structure is found */
    register Path *p;	      /* pointer to new Path structure */
    DIR     	  *d;	      /* for reading directory */
    register struct dirent *dp; /* entry in directory */
    
    ln = Lst_Find (openDirectories, (ClientData)name, DirFindName);
    if (ln != NILLNODE) {
	p = (Path *)Lst_Datum (ln);
	if (Lst_Member(path, (ClientData)p) == NILLNODE) {
	    p->refCount += 1;
	    (void)Lst_AtEnd (path, (ClientData)p);
	}
    } else {
	if (DEBUG(DIR)) {
	    printf("Caching %s...", name);
	    fflush(stdout);
	}
	
	if ((d = opendir (name)) != (DIR *) NULL) {
	    p = (Path *) emalloc (sizeof (Path));
	    p->name = strdup (name);
	    p->hits = 0;
	    p->refCount = 1;
	    Hash_InitTable (&p->files, -1);
	    
	    /*
	     * Skip the first two entries -- these will *always* be . and ..
	     */
	    (void)readdir(d);
	    (void)readdir(d);
	    
	    while ((dp = readdir (d)) != (struct dirent *) NULL) {
#ifdef sun
		/*
		 * The sun directory library doesn't check for a 0 inode
		 * (0-inode slots just take up space), so we have to do
		 * it ourselves.
		 */
		if (dp->d_fileno == 0) {
		    continue;
		}
#endif sun
		(void)Hash_CreateEntry(&p->files, dp->d_name, (Boolean *)NULL);
	    }
	    (void) closedir (d);
	    (void)Lst_AtEnd (openDirectories, (ClientData)p);
	    (void)Lst_AtEnd (path, (ClientData)p);
	}
	if (DEBUG(DIR)) {
	    printf("done\n");
	}
    }
}

/*-
 *-----------------------------------------------------------------------
 * Dir_CopyDir --
 *	Callback function for duplicating a search path via Lst_Duplicate.
 *	Ups the reference count for the directory.
 *
 * Results:
 *	Returns the Path it was given.
 *
 * Side Effects:
 *	The refCount of the path is incremented.
 *
 *-----------------------------------------------------------------------
 */
ClientData
Dir_CopyDir(p)
    Path    *p;	  	/* Directory descriptor to copy */
{
    p->refCount += 1;

    return ((ClientData)p);
}

/*-
 *-----------------------------------------------------------------------
 * Dir_MakeFlags --
 *	Make a string by taking all the directories in the given search
 *	path and preceding them by the given flag. Used by the suffix
 *	module to create variables for compilers based on suffix search
 *	paths.
 *
 * Results:
 *	The string mentioned above. Note that there is no space between
 *	the given flag and each directory. The empty string is returned if
 *	Things don't go well.
 *
 * Side Effects:
 *	None
 *-----------------------------------------------------------------------
 */
char *
Dir_MakeFlags (flag, path)
    char	  *flag;  /* flag which should precede each directory */
    Lst	    	  path;	  /* list of directories */
{
    char	  *str;	  /* the string which will be returned */
    char	  *tstr;  /* the current directory preceded by 'flag' */
    LstNode	  ln;	  /* the node of the current directory */
    Path	  *p;	  /* the structure describing the current directory */
    
    str = strdup ("");
    
    if (Lst_Open (path) == SUCCESS) {
	while ((ln = Lst_Next (path)) != NILLNODE) {
	    p = (Path *) Lst_Datum (ln);
	    tstr = str_concat (flag, p->name, 0);
	    str = str_concat (str, tstr, STR_ADDSPACE | STR_DOFREE);
	}
	Lst_Close (path);
    }
    
    return (str);
}

/*-
 *-----------------------------------------------------------------------
 * Dir_Destroy --
 *	Nuke a directory descriptor, if possible. Callback procedure
 *	for the suffixes module when destroying a search path.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	If no other path references this directory (refCount == 0),
 *	the Path and all its data are freed.
 *
 *-----------------------------------------------------------------------
 */
void
Dir_Destroy (p)
    Path    	  *p;	    /* The directory descriptor to nuke */
{
    p->refCount -= 1;

    if (p->refCount == 0) {
	LstNode	ln;

	ln = Lst_Member (openDirectories, (ClientData)p);
	(void) Lst_Remove (openDirectories, ln);

	Hash_DeleteTable (&p->files);
	free((Address)p->name);
	free((Address)p);
    }
}

/*-
 *-----------------------------------------------------------------------
 * Dir_ClearPath --
 *	Clear out all elements of the given search path. This is different
 *	from destroying the list, notice.
 *
 * Results:
 *	None.
 *
 * Side Effects:
 *	The path is set to the empty list.
 *
 *-----------------------------------------------------------------------
 */
void
Dir_ClearPath(path)
    Lst	    path; 	/* Path to clear */
{
    Path    *p;
    while (!Lst_IsEmpty(path)) {
	p = (Path *)Lst_DeQueue(path);
	Dir_Destroy(p);
    }
}
	    

/*-
 *-----------------------------------------------------------------------
 * Dir_Concat --
 *	Concatenate two paths, adding the second to the end of the first.
 *	Makes sure to avoid duplicates.
 *
 * Results:
 *	None
 *
 * Side Effects:
 *	Reference counts for added dirs are upped.
 *
 *-----------------------------------------------------------------------
 */
void
Dir_Concat(path1, path2)
    Lst	    path1;  	/* Dest */
    Lst	    path2;  	/* Source */
{
    LstNode ln;
    Path    *p;

    for (ln = Lst_First(path2); ln != NILLNODE; ln = Lst_Succ(ln)) {
	p = (Path *)Lst_Datum(ln);
	if (Lst_Member(path1, (ClientData)p) == NILLNODE) {
	    p->refCount += 1;
	    (void)Lst_AtEnd(path1, (ClientData)p);
	}
    }
}

/********** DEBUG INFO **********/
void
Dir_PrintDirectories()
{
    LstNode	ln;
    Path	*p;
    
    printf ("#*** Directory Cache:\n");
    printf ("# Stats: %d hits %d misses %d near misses %d losers (%d%%)\n",
	      hits, misses, nearmisses, bigmisses,
	      (hits+bigmisses+nearmisses ?
	       hits * 100 / (hits + bigmisses + nearmisses) : 0));
    printf ("# %-20s referenced\thits\n", "directory");
    if (Lst_Open (openDirectories) == SUCCESS) {
	while ((ln = Lst_Next (openDirectories)) != NILLNODE) {
	    p = (Path *) Lst_Datum (ln);
	    printf ("# %-20s %10d\t%4d\n", p->name, p->refCount, p->hits);
	}
	Lst_Close (openDirectories);
    }
}

static int DirPrintDir (p) Path *p; { printf ("%s ", p->name); return (0); }

void
Dir_PrintPath (path)
    Lst	path;
{
    Lst_ForEach (path, DirPrintDir, (ClientData)0);
}