/* src/vmcore/suck.c - functions to read LE ordered types from a buffer

   Copyright (C) 1996-2005, 2006, 2007 R. Grafl, A. Krall, C. Kruegel,
   C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring,
   E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich,
   J. Wenninger, Institut f. Computersprachen - TU Wien

   This file is part of CACAO.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.

   $Id: suck.c 7813 2007-04-25 19:20:13Z twisti $

*/


#include "config.h"

#include <assert.h>
#include <dirent.h>
#include <sys/stat.h>
#include <stdlib.h>

#include "vm/types.h"

#include "arch.h"

#include "mm/memory.h"

#include "threads/lock-common.h"

#include "toolbox/list.h"
#include "toolbox/logging.h"
#include "toolbox/util.h"

#include "vm/exceptions.h"
#include "vm/properties.h"
#include "vm/vm.h"

#include "vmcore/loader.h"
#include "vmcore/options.h"
#include "vmcore/suck.h"
#include "vmcore/zip.h"


/* global variables ***********************************************************/

list_t *list_classpath_entries;


/* suck_init *******************************************************************

   Initializes the suck subsystem like initializing the classpath
   entries list.

*******************************************************************************/

bool suck_init(void)
{
	list_classpath_entries = list_create(OFFSET(list_classpath_entry, linkage));

	/* everything's ok */

	return true;
}


/* scandir_filter **************************************************************

   Filters for zip/jar files.

*******************************************************************************/

#if defined(__LINUX__)
static int scandir_filter(const struct dirent *a)
#else
static int scandir_filter(struct dirent *a)
#endif
{
	s4 namlen;

#if defined(_DIRENT_HAVE_D_NAMLEN)
	namlen = a->d_namlen;
#else
	namlen = strlen(a->d_name);
#endif

	if ((strncasecmp(a->d_name + namlen - 4, ".zip", 4) == 0) ||
		(strncasecmp(a->d_name + namlen - 4, ".jar", 4) == 0))
		return 1;

	return 0;
}


/* suck_add ********************************************************************

   Adds a classpath to the global classpath entries list.

*******************************************************************************/

void suck_add(char *classpath)
{
	list_classpath_entry *lce;
	char                 *start;
	char                 *end;
	char                 *filename;
	s4                    filenamelen;
	bool                  is_zip;
	char                 *cwd;
	s4                    cwdlen;
#if defined(ENABLE_ZLIB)
	hashtable            *ht;
#endif

	/* parse the classpath string */

	for (start = classpath; (*start) != '\0'; ) {

		/* search for ':' delimiter to get the end of the current entry */
		for (end = start; ((*end) != '\0') && ((*end) != ':'); end++);

		if (start != end) {
			is_zip = false;
			filenamelen = end - start;

			if (filenamelen > 4) {
				if ((strncasecmp(end - 4, ".zip", 4) == 0) ||
					(strncasecmp(end - 4, ".jar", 4) == 0)) {
					is_zip = true;
				}
			}

			/* save classpath entries as absolute pathnames */

			cwd = NULL;
			cwdlen = 0;

			if (*start != '/') {                      /* XXX fix me for win32 */
				cwd = _Jv_getcwd();
				cwdlen = strlen(cwd) + strlen("/");
			}

			/* allocate memory for filename and fill it */

			filename = MNEW(char, filenamelen + cwdlen + strlen("/") +
							strlen("0"));

			if (cwd) {
				strcpy(filename, cwd);
				strcat(filename, "/");
				strncat(filename, start, filenamelen);

				/* add cwd length to file length */
				filenamelen += cwdlen;

			} else {
				strncpy(filename, start, filenamelen);
				filename[filenamelen] = '\0';
			}

			lce = NULL;

			if (is_zip) {
#if defined(ENABLE_ZLIB)
				ht = zip_open(filename);

				if (ht != NULL) {
					lce = NEW(list_classpath_entry);

					lce->type      = CLASSPATH_ARCHIVE;
					lce->htclasses = ht;
					lce->path      = filename;
					lce->pathlen   = filenamelen;

					/* SUN compatible -verbose:class output */

					if (opt_verboseclass)
						printf("[Opened %s]\n", filename);
				}

#else
				vm_abort("suck_add: zip/jar files not supported");
#endif
			}
			else {
				if (filename[filenamelen - 1] != '/') {/* XXX fixme for win32 */
					filename[filenamelen] = '/';
					filename[filenamelen + 1] = '\0';
					filenamelen++;
				}

				lce = NEW(list_classpath_entry);

				lce->type    = CLASSPATH_PATH;
				lce->path    = filename;
				lce->pathlen = filenamelen;
			}

			/* add current classpath entry, if no error */

			if (lce != NULL)
				list_add_last(list_classpath_entries, lce);
		}

		/* goto next classpath entry, skip ':' delimiter */

		if ((*end) == ':')
			start = end + 1;
		else
			start = end;
	}
}


/* suck_add_from_property ******************************************************

   Adds a classpath form a property entry to the global classpath
   entries list.

*******************************************************************************/

void suck_add_from_property(char *key)
{
	char           *value;
	char           *start;
	char           *end;
	char           *path;
	s4              pathlen;
	struct dirent **namelist;
	s4              n;
	s4              i;
	s4              namlen;
	char           *tmpbootclasspath;

	/* get the property value */

	value = properties_get(key);

	if (value == NULL)
		return;

	/* get the directory entries of the property */

	for (start = value; (*start) != '\0'; ) {

		/* search for ':' delimiter to get the end of the current entry */

		for (end = start; ((*end) != '\0') && ((*end) != ':'); end++);

		/* found an entry */

		if (start != end) {
			/* allocate memory for the path entry */

			pathlen = end - start;
			path = MNEW(char, pathlen + strlen("0"));

			/* copy and terminate the string */

			strncpy(path, start, pathlen);
			path[pathlen] = '\0';

			/* Reset namelist to NULL for the freeing in an error case
			   (see below). */

			namelist = NULL;

			/* scan the directory found for zip/jar files */

			n = scandir(path, &namelist, scandir_filter, alphasort);

			/* On error, just continue, this should be ok. */

			if (n > 0) {
				for (i = 0; i < n; i++) {
#if defined(_DIRENT_HAVE_D_NAMLEN)
					namlen = namelist[i]->d_namlen;
#else
					namlen = strlen(namelist[i]->d_name);
#endif

					/* reallocate memory for bootclasspath */

					tmpbootclasspath = MNEW(char,
											pathlen + strlen("/") + namlen +
											strlen(":") +
											strlen(_Jv_bootclasspath) +
											strlen("0"));

					/* prepend the file found to bootclasspath */

					strcpy(tmpbootclasspath, path);
					strcat(tmpbootclasspath, "/");
					strcat(tmpbootclasspath, namelist[i]->d_name);
					strcat(tmpbootclasspath, ":");

					strcat(tmpbootclasspath, _Jv_bootclasspath);

					/* free old bootclasspath memory */

					MFREE(_Jv_bootclasspath, u1, strlen(_Jv_bootclasspath));

					/* and set the new bootclasspath */

					_Jv_bootclasspath = tmpbootclasspath;

					/* free the memory allocated by scandir */
					/* (We use `free` as the memory came from the C library.) */

					free(namelist[i]);
				}
			}

			/* On some systems (like Linux) when n == 0, then namelist
			   returned from scnadir is NULL, thus we don't have to
			   free it.
			   (Use `free` as the memory came from the C library.) */

			if (namelist != NULL)
				free(namelist);

			MFREE(path, char, pathlen + strlen("0"));
		}

		/* goto next entry, skip ':' delimiter */

		if ((*end) == ':')
			start = end + 1;
		else
			start = end;
	}
}


/* suck_check_classbuffer_size *************************************************

   Assert that at least <len> bytes are left to read <len> is limited
   to the range of non-negative s4 values.

*******************************************************************************/

bool suck_check_classbuffer_size(classbuffer *cb, s4 len)
{
#ifdef ENABLE_VERIFIER
	if (len < 0 || ((cb->data + cb->size) - cb->pos) < len) {
		exceptions_throw_classformaterror((cb)->class, "Truncated class file");
		return false;
	}
#endif /* ENABLE_VERIFIER */

	return true;
}


u1 suck_u1(classbuffer *cb)
{
	u1 a;

	a = SUCK_BE_U1(cb->pos);
	cb->pos++;

	return a;
}


u2 suck_u2(classbuffer *cb)
{
	u2 a;

	a = SUCK_BE_U2(cb->pos);
	cb->pos += 2;

	return a;
}


u4 suck_u4(classbuffer *cb)
{
	u4 a;

	a = SUCK_BE_U4(cb->pos);
	cb->pos += 4;

	return a;
}


u8 suck_u8(classbuffer *cb)
{
#if U8_AVAILABLE == 1
	u8 a;

	a = SUCK_BE_U8(cb->pos);
	cb->pos += 8;

	return a;
#else
	u8 v;

	v.high = suck_u4(cb);
	v.low = suck_u4(cb);

	return v;
#endif
}


float suck_float(classbuffer *cb)
{
	float f;

#if WORDS_BIGENDIAN == 0
	u1 buffer[4];
	u2 i;

	for (i = 0; i < 4; i++)
		buffer[3 - i] = suck_u1(cb);

	MCOPY((u1 *) (&f), buffer, u1, 4);
#else
	suck_nbytes((u1*) (&f), cb, 4);
#endif

	assert(sizeof(float) == 4);
	
	return f;
}


double suck_double(classbuffer *cb)
{
	double d;

#if WORDS_BIGENDIAN == 0
	u1 buffer[8];
	u2 i;	

# if defined(__ARM__) && defined(__ARMEL__) && !defined(__VFP_FP__)
	/*
	 * On little endian ARM processors when using FPA, word order
	 * of doubles is still big endian. So take that into account
	 * here. When using VFP, word order of doubles follows byte
	 * order. (michi 2005/07/24)
	 */
	for (i = 0; i < 4; i++)
		buffer[3 - i] = suck_u1(cb);
	for (i = 0; i < 4; i++)
		buffer[7 - i] = suck_u1(cb);
# else
	for (i = 0; i < 8; i++)
		buffer[7 - i] = suck_u1(cb);
# endif /* defined(__ARM__) && ... */

	MCOPY((u1 *) (&d), buffer, u1, 8);
#else 
	suck_nbytes((u1*) (&d), cb, 8);
#endif

	assert(sizeof(double) == 8);
	
	return d;
}


/* suck_nbytes *****************************************************************

   Transfer block of classfile data into a buffer.

*******************************************************************************/

void suck_nbytes(u1 *buffer, classbuffer *cb, s4 len)
{
	MCOPY(buffer, cb->pos, u1, len);
	cb->pos += len;
}


/* suck_skip_nbytes ************************************************************

   Skip block of classfile data.

*******************************************************************************/

void suck_skip_nbytes(classbuffer *cb, s4 len)
{
	cb->pos += len;
}


/* suck_start ******************************************************************

   Returns true if classbuffer is already loaded or a file for the
   specified class has succussfully been read in. All directories of
   the searchpath are used to find the classfile (<classname>.class).
   Returns NULL if no classfile is found and writes an error message.
	
*******************************************************************************/

classbuffer *suck_start(classinfo *c)
{
	list_classpath_entry *lce;
	char                 *filename;
	s4                    filenamelen;
	char                 *path;
	FILE                 *classfile;
	s4                    len;
	struct stat           buffer;
	classbuffer          *cb;

	/* initialize return value */

	cb = NULL;

	/* get the classname as char string (do it here for the warning at
       the end of the function) */

	filenamelen = utf_bytes(c->name) + strlen(".class") + strlen("0");
	filename = MNEW(char, filenamelen);

	utf_copy(filename, c->name);
	strcat(filename, ".class");

	/* walk through all classpath entries */

	for (lce = list_first(list_classpath_entries); lce != NULL && cb == NULL;
		 lce = list_next(list_classpath_entries, lce)) {
#if defined(ENABLE_ZLIB)
		if (lce->type == CLASSPATH_ARCHIVE) {

			/* enter a monitor on zip/jar archives */

			LOCK_MONITOR_ENTER(lce);

			/* try to get the file in current archive */

			cb = zip_get(lce, c);

			/* leave the monitor */

			LOCK_MONITOR_EXIT(lce);

		} else {
#endif /* defined(ENABLE_ZLIB) */
			path = MNEW(char, lce->pathlen + filenamelen);
			strcpy(path, lce->path);
			strcat(path, filename);

			classfile = fopen(path, "r");

			if (classfile) {                                   /* file exists */
				if (!stat(path, &buffer)) {            /* read classfile data */
					cb = NEW(classbuffer);
					cb->class = c;
					cb->size  = buffer.st_size;
					cb->data  = MNEW(u1, cb->size);
					cb->pos   = cb->data;
					cb->path  = lce->path;

					/* read class data */

					len = fread(cb->data, 1, cb->size, classfile);

					if (len != buffer.st_size) {
						suck_stop(cb);
/*  						if (ferror(classfile)) { */
/*  						} */
					}

					/* close the class file */

					fclose(classfile);
				}
			}

			MFREE(path, char, lce->pathlen + filenamelen);
#if defined(ENABLE_ZLIB)
		}
#endif
	}

	if (opt_verbose)
		if (cb == NULL)
			dolog("Warning: Can not open class file '%s'", filename);

	MFREE(filename, char, filenamelen);

	return cb;
}


/* suck_stop *******************************************************************

   Frees memory for buffer with classfile data.

   CAUTION: This function may only be called if buffer has been
   allocated by suck_start with reading a file.
	
*******************************************************************************/

void suck_stop(classbuffer *cb)
{
	/* free memory */

	MFREE(cb->data, u1, cb->size);
	FREE(cb, classbuffer);
}


/*
 * These are local overrides for various environment variables in Emacs.
 * Please do not remove this and leave it at the end of the file, where
 * Emacs will automagically detect them.
 * ---------------------------------------------------------------------
 * Local variables:
 * mode: c
 * indent-tabs-mode: t
 * c-basic-offset: 4
 * tab-width: 4
 * End:
 */