Merge in data tree sharing, minus locking support, plus a bugfix or two

* prof_int.h (SHARE_TREE_DATA): Define.
(struct _prf_file_t) [SHARE_TREE_DATA]: Make data field a pointer rather than
an array.
(struct global_shared_profile_data): New type, for profile library global
data.
(krb5int_profile_shared_data): Declare new variable.
(g_shared_trees): New macro, refers to a field in the global data.
(PROFILE_FILE_SHARED): New flag macro.
* prof_file.c (krb5int_profile_shared_data): Initialize here.
(profile_open_file) [SHARE_TREE_DATA]: Scan g_shared_trees for an entry with
the same filename.  If found, increment its reference count, update it, and
return it; otherwise, allocate a new one, and add it to the list after filling
it in.
(profile_dereference_data): New function.  Decrement reference count if
SHARE_TREE_DATA, and free the data if appropriate.
(profile_free_file): Call profile_dereference_data.
(profile_free_file_data) [SHARE_TREE_DATA]: If the SHARED flag is set, remove
it from the g_shared_trees list before freeing.  Free up the allocated space.
* prof_set.c (rw_setup) [SHARE_TREE_DATA]: If the object's data is shared, copy
it into a new data structure not in the global shared list, and dereference the
old one.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@15060 dc483132-0cff-0310-8789-dd5450dbe970

4 files changed, 152 insertions, 9 deletions

diff --git a/src/util/profile/ChangeLog b/src/util/profile/ChangeLog
index cf7c5360f2..bcf9c2f106 100644
--- a/src/util/profile/ChangeLog
+++ b/src/util/profile/ChangeLog
@@ -1,3 +1,28 @@
+2002-12-20  Ken Raeburn  <raeburn@mit.edu>
+
+	* prof_int.h (SHARE_TREE_DATA): Define.
+	(struct _prf_file_t) [SHARE_TREE_DATA]: Make data field a pointer
+	rather than an array.
+	(struct global_shared_profile_data): New type, for profile library
+	global data.
+	(krb5int_profile_shared_data): Declare new variable.
+	(g_shared_trees): New macro, refers to a field in the global data.
+	(PROFILE_FILE_SHARED): New flag macro.
+	* prof_file.c (krb5int_profile_shared_data): Initialize here.
+	(profile_open_file) [SHARE_TREE_DATA]: Scan g_shared_trees for an
+	entry with the same filename.  If found, increment its reference
+	count, update it, and return it; otherwise, allocate a new one,
+	and add it to the list after filling it in.
+	(profile_dereference_data): New function.  Decrement reference
+	count if SHARE_TREE_DATA, and free the data if appropriate.
+	(profile_free_file): Call profile_dereference_data.
+	(profile_free_file_data) [SHARE_TREE_DATA]: If the SHARED flag is
+	set, remove it from the g_shared_trees list before freeing.  Free
+	up the allocated space.
+	* prof_set.c (rw_setup) [SHARE_TREE_DATA]: If the object's data is
+	shared, copy it into a new data structure not in the global shared
+	list, and dereference the old one.
+
 2002-12-06  Ken Raeburn  <raeburn@mit.edu>
 
 	* prof_int.h: Include Mac OS X versions of header files if
diff --git a/src/util/profile/prof_file.c b/src/util/profile/prof_file.c
index 4ffe7e1384..e9da626e3d 100644
--- a/src/util/profile/prof_file.c
+++ b/src/util/profile/prof_file.c
@@ -28,13 +28,18 @@
 #define stat _stat
 #endif
 
+#ifdef SHARE_TREE_DATA
+struct global_shared_profile_data krb5int_profile_shared_data = {
+    0
+};
+#endif
+
 #ifndef PROFILE_USES_PATHS
 #include <FSp_fopen.h>
 
 static OSErr GetMacOSTempFilespec (
 	const	FSSpec*	inFilespec,
 			FSSpec*	outFilespec);
-
 #endif
 
 static int rw_access(filespec)
@@ -80,7 +85,36 @@ errcode_t profile_open_file(filespec, ret_prof)
 	if (!prf)
 		return ENOMEM;
 	memset(prf, 0, sizeof(struct _prf_file_t));
+	prf->magic = PROF_MAGIC_FILE;
+
+#ifdef SHARE_TREE_DATA
+	for (data = g_shared_trees; data; data = data->next) {
+	    if (!strcmp(data->filespec, filespec)
+		/* Check that current uid has read access.  */
+		&& access(data->filespec, R_OK) == 0)
+		break;
+	}
+	if (data) {
+	    retval = profile_update_file_data(data);
+	    data->refcount++;
+	    prf->data = data;
+	    *ret_prof = prf;
+	    return retval;
+	}
+	data = malloc(sizeof(struct _prf_data_t));
+	if (data == NULL) {
+	    free(prf);
+	    return ENOMEM;
+	}
+	memset(data, 0, sizeof(*data));
+	prf->data = data;
+#else
 	data = prf->data;
+#endif
+
+	data->magic = PROF_MAGIC_FILE_DATA;
+	data->refcount = 1;
+	data->comment = 0;
 
 	len = strlen(filespec)+1;
 	if (filespec[0] == '~' && filespec[1] == '/') {
@@ -98,9 +132,6 @@ errcode_t profile_open_file(filespec, ret_prof)
 		strcat(data->filespec, filespec+1);
 	} else
 		strcpy(data->filespec, filespec);
-	prf->magic = PROF_MAGIC_FILE;
-	data->magic = PROF_MAGIC_FILE_DATA;
-	data->refcount = 1;
 
 	retval = profile_update_file(prf);
 	if (retval) {
@@ -108,6 +139,12 @@ errcode_t profile_open_file(filespec, ret_prof)
 		return retval;
 	}
 
+#ifdef SHARE_TREE_DATA
+	data->next = g_shared_trees;
+	data->flags |= PROFILE_FILE_SHARED;
+	g_shared_trees = data;
+#endif
+
 	*ret_prof = prf;
 	return 0;
 }
@@ -276,16 +313,47 @@ errout:
 }
 
 
+void profile_dereference_data(prf_data_t data)
+{
+#ifdef SHARE_TREE_DATA
+    data->refcount--;
+    if (data->refcount == 0)
+	profile_free_file_data(data);
+#else
+    profile_free_file_data(data);
+#endif
+}
+
 void profile_free_file(prf)
 	prf_file_t prf;
 {
-	profile_free_file_data(prf->data);
-	free(prf);
+    profile_dereference_data(prf->data);
+    free(prf);
 }
 
 void profile_free_file_data(data)
 	prf_data_t data;
 {
+#ifdef SHARE_TREE_DATA
+    if (data->flags & PROFILE_FILE_SHARED) {
+	/* Remove from linked list.  */
+	if (g_shared_trees == data)
+	    g_shared_trees = data->next;
+	else {
+	    prf_data_t prev, next;
+	    prev = g_shared_trees;
+	    next = prev->next;
+	    while (next) {
+		if (next == data) {
+		    prev->next = next->next;
+		    break;
+		}
+		prev = next;
+		next = next->next;
+	    }
+	}
+    }
+#endif
 #ifdef PROFILE_USES_PATHS
 	if (data->filespec)
 		free(data->filespec);
@@ -295,6 +363,9 @@ void profile_free_file_data(data)
 	if (data->comment)
 		free(data->comment);
 	data->magic = 0;
+#ifdef SHARE_TREE_DATA
+	free(data);
+#endif
 }
 
 errcode_t profile_close_file(prf)
@@ -308,4 +379,3 @@ errcode_t profile_close_file(prf)
 	profile_free_file(prf);
 	return 0;
 }
-
diff --git a/src/util/profile/prof_int.h b/src/util/profile/prof_int.h
index 00fd2847b1..ead23dc3a2 100644
--- a/src/util/profile/prof_int.h
+++ b/src/util/profile/prof_int.h
@@ -30,6 +30,8 @@
 
 typedef long prf_magic_t;
 
+#define SHARE_TREE_DATA
+
 /*
  * This is the structure which stores the profile information for a
  * particular configuration file.
@@ -50,17 +52,31 @@ typedef struct _prf_data_t *prf_data_t;
 
 struct _prf_file_t {
 	prf_magic_t	magic;
+#ifdef SHARE_TREE_DATA
+	struct _prf_data_t	*data;
+#else
 	struct _prf_data_t	data[1];
+#endif
 	struct _prf_file_t *next;
 };
 
 typedef struct _prf_file_t *prf_file_t;
 
+#ifdef SHARE_TREE_DATA
+struct global_shared_profile_data {
+	/* This is the head of the global list of shared trees */
+	prf_data_t trees;
+};
+extern struct global_shared_profile_data krb5int_profile_shared_data;
+#define g_shared_trees		(krb5int_profile_shared_data.trees)
+#endif /* SHARE_TREE_DATA */
+
 /*
  * The profile flags
  */
 #define PROFILE_FILE_RW		0x0001
 #define PROFILE_FILE_DIRTY	0x0002
+#define PROFILE_FILE_SHARED	0x0004
 
 /*
  * This structure defines the high-level, user visible profile_t
diff --git a/src/util/profile/prof_set.c b/src/util/profile/prof_set.c
index 4c6ccb29d5..5abf5ec9af 100644
--- a/src/util/profile/prof_set.c
+++ b/src/util/profile/prof_set.c
@@ -24,7 +24,7 @@ static errcode_t rw_setup(profile)
 	profile_t	profile;
 {
    	prf_file_t	file;
-	errcode_t	retval;
+	errcode_t	retval = 0;
 
 	if (!profile)
 		return PROF_NO_PROFILE;
@@ -39,7 +39,39 @@ static errcode_t rw_setup(profile)
 	/* Don't update the file if we've already made modifications */
 	if (file->data->flags & PROFILE_FILE_DIRTY)
 		return 0;
-			
+
+#ifdef SHARE_TREE_DATA
+	if ((file->data->flags & PROFILE_FILE_SHARED) != 0) {
+	    prf_data_t new_data;
+	    new_data = malloc(sizeof(struct _prf_data_t));
+	    if (new_data == NULL) {
+		retval = ENOMEM;
+	    } else {
+		*new_data = *file->data;
+		/* We can blow away the information because update
+		   will be called further down */
+		new_data->comment = NULL;
+		new_data->root = NULL;
+		new_data->flags &= ~PROFILE_FILE_SHARED;
+		new_data->timestamp = 0;
+		/* copy the file spec */
+		new_data->filespec = malloc(strlen(file->data->filespec) + 1);
+		if (new_data->filespec == NULL) {
+		    retval = ENOMEM;
+		} else {
+		    strcpy (new_data->filespec, file->data->filespec);
+		}
+	    }
+
+	    if (retval != 0) {
+		free(new_data);
+		return retval;
+	    }
+	    profile_dereference_data(file->data);
+	    file->data = new_data;
+	}
+#endif /* SHARE_TREE_DATA */
+
 	retval = profile_update_file(file);
 	
 	return retval;