pathkey.c   [plain text]

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                      by AT&T Knowledge Ventures                      *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#pragma prototyped
/*
 * Glenn Fowler
 * AT&T Bell Laboratories
 *
 * generate 14 char lookup key for lang path in key
 * based on 32-bit checksum on path
 *
 * if key==0 then space is malloc'd
 * if attr != 0 then attribute var assignments placed here:
 *	ATTRIBUTES	list of attribute names
 */

#include <ast.h>
#include <ctype.h>
#include <fs3d.h>
#include <preroot.h>

char*
pathkey(char* key, char* attr, const char* lang, const char* tool, const char* apath)
{
	register char*		path = (char*)apath;
	register char*		s;
	register char*		k;
	char*			t;
	char*			flags;
	char**			p;
	int			c;
	unsigned long		n;
	char			buf[15];
	char*			usr[16];
	char*			env[elementsof(usr) + 3];
	char*			ver[2];
	char			tmp[PATH_MAX];

	static char		let[] = "ABCDEFGHIJKLMNOP";

	if (!key)
		key = buf;
	if (tool && streq(tool, "mam"))
	{
		for (n = 0; *path; path++)
			n = n * 0x63c63cd9L + *path + 0x9c39c33dL;
		k = key;
		for (n &= 0xffffffffL; n; n >>= 4)
			*k++ = let[n & 0xf];
		*k = 0;
	}
	else
	{
		for (c = 0; c < elementsof(env); c++)
			env[c] = 0;
		n = 0;

		/*
		 * trailing flags in path
		 */

		if (flags = strchr(path, ' '))
		{
			if (flags == path)
				flags = 0;
			else
			{
				strcpy(tmp, path);
				*(flags = tmp + (flags - path)) = 0;
				path = tmp;
			}
		}

		/*
		 * 3D
		 */

		if (fs3d(FS3D_TEST) && (c = mount(path, tmp, FS3D_GET|FS3D_ALL|FS3D_SIZE(PATH_MAX), NiL)) > 1 && c < PATH_MAX)
			path = tmp;

		/*
		 * preroot
		 */

		if (attr)
			attr = strcopy(attr, "PREROOT='");
#if FS_PREROOT
		if (k = getenv(PR_BASE))
		{
			if (s = strrchr(k, '/'))
				k = s + 1;
			n = memsum(k, strlen(k), n);
		}
		if (attr && (getpreroot(attr, path) || getpreroot(attr, NiL)))
			attr += strlen(attr);
#else
		if ((k = getenv("VIRTUAL_ROOT")) && *k == '/')
		{
			n = memsum(k, strlen(k), n);
			if (attr)
				attr = strcopy(attr, k);
		}
#endif

		/*
		 * universe
		 */

		if (attr)
			attr = strcopy(attr, "' UNIVERSE='");
		if (k = astconf("UNIVERSE", NiL, NiL))
		{
			n = memsum(k, strlen(k), n);
			if (attr)
				attr = strcopy(attr, k);
		}

		/*
		 * environment
		 *
		 *	${PROBE_ATTRIBUTES} || ${VERSION_ENVIRONMENT} : list of alternate env vars
		 *	${VERSION_ENVIRONMENT}	: list of alternate env vars
		 *	${VERSION_<lang>}
		 *	${VERSION_<base(path)>}
		 *	${<toupper(base(path))>VER}
		 *	${OBJTYPE}
		 */

		if (attr)
			*attr++ = '\'';
		c = 0;
		usr[c++] = "OBJTYPE";
		if (!(k = getenv("PROBE_ATTRIBUTES")))
			k = getenv("VERSION_ENVIRONMENT");
		if (k)
			while (c < elementsof(usr))
			{
				while (*k && (*k == ':' || *k == ' '))
					k++;
				if (!*k)
					break;
				usr[c++] = k;
				while (*k && *k != ':' && *k != ' ')
					k++;
			}
		usr[c] = 0;
		ver[0] = (char*)lang;
		ver[1] = k = (s = strrchr(path, '/')) ? s + 1 : path;
		s = buf;
		if (isdigit(*k))
		{
			if (*k == '3' && *(k + 1) == 'b')
			{
				/*
				 * cuteness never pays
				 */

				k += 2;
				*s++ = 'B';
				*s++ = 'B';
				*s++ = 'B';
			}
			else
				*s++ = 'U';
		}
		for (; (c = *k) && s < &buf[sizeof(buf) - 1]; k++)
		{
			if (!isalnum(c))
				c = '_';
			else if (islower(c))
				c = toupper(c);
			*s++ = c;
		}
		*s = 0;
		for (p = environ; *p; p++)
		{
			s = "VERSION_";
			for (k = *p; *k && *k == *s; k++, s++);
			if (*k && !*s)
			{
				for (c = 0; c < elementsof(ver); c++)
					if (!env[c] && (s = ver[c]))
					{
						for (t = k; *t && *t != '=' && *t++ == *s; s++);
						if (*t == '=' && (!*s || (s - ver[c]) > 1))
						{
							env[c] = *p;
							goto found;
						}
					}
			}
			if (!env[2])
			{
				s = buf;
				for (k = *p; *k && *s++ == *k; k++);
				if ((s - buf) > 2 && k[0] == 'V' && k[1] == 'E' && k[2] == 'R' && k[3] == '=')
				{
					env[2] = *p;
					goto found;
				}
			}
			for (c = 0; c < elementsof(usr) && (s = usr[c]); c++)
				if (!env[c + elementsof(env) - elementsof(usr)])
				{
					for (k = *p; *k && *k == *s; k++, s++);
					if (*k == '=' && (!*s || *s == ':' || *s == ' '))
					{
						env[c + elementsof(env) - elementsof(usr)] = *p;
						goto found;
					}
				}
		found:	;
		}
		for (c = 0; c < elementsof(env); c++)
			if (k = env[c])
			{
				if (attr)
				{
					*attr++ = ' ';
					while ((*attr++ = *k++) != '=');
					*attr++ = '\'';
					attr = strcopy(attr, k);
					*attr++ = '\'';
				}
				else
					while (*k && *k++ != '=');
				n = memsum(k, strlen(k), n);
			}
		if (attr)
		{
			attr = strcopy(attr, " ATTRIBUTES='PREROOT UNIVERSE");
			for (c = 0; c < elementsof(env); c++)
				if (k = env[c])
				{
					*attr++ = ' ';
					while ((*attr = *k++) != '=')
						attr++;
				}
			*attr++ = '\'';
			*attr = 0;
		}

		/*
		 * now the normal stuff
		 */

		if (flags)
			*flags = ' ';
		s = path + strlen(path);
		sfsprintf(key, 15, "%08lX", memsum(path, s - path, n));
		k = key + 14;
		*k = 0;
		if (!flags)
			t = path;
		else if ((t = s - 4) < flags)
			t = flags + 1;
		for (;;)
		{
			if (--s < t)
			{
				if (t == path)
					break;
				s = flags - 2;
				t = path;
			}
			if (*s != '/' && *s != ' ')
			{
				*--k = *s;
				if (k <= key + 8)
					break;
			}
		}
		while (k > key + 8)
			*--k = '.';
	}
	return key == buf ? strdup(key) : key;
}