lib/properties: Common code for handling properties.

The common bits from lib/report/properties.[c|h] have
been moved to lib/properties/prop_common.[c|h] to allow
re-use of property handling functionality without
polluting the report handling functionality.

Signed-off-by: Tony Asleson <tasleson@redhat.com>

lib/properties/prop_common.c

@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2013 Red Hat, Inc. All rights reserved.
+ *
+ * This file is part of LVM2.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU Lesser General Public License v.2.1.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "lib.h"
+#include "prop_common.h"
+
+int prop_not_implemented_get(const void *obj, struct lvm_property_type *prop)
+{
+	log_errno(ENOSYS, "Function not implemented");
+
+	return 0;
+}
+
+int prop_not_implemented_set(void *obj, struct lvm_property_type *prop)
+{
+	log_errno(ENOSYS, "Function not implemented");
+
+	return 0;
+}
+
+int prop_get_property(struct lvm_property_type *p, const void *obj,
+		struct lvm_property_type *prop,
+		unsigned type)
+{
+	while (p->id[0]) {
+		if (!strcmp(p->id, prop->id))
+			break;
+		p++;
+	}
+	if (!p->id[0]) {
+		log_errno(EINVAL, "Invalid property name %s", prop->id);
+		return 0;
+	}
+	if (!(p->type & type)) {
+		log_errno(EINVAL, "Property name %s does not match type %d",
+			  prop->id, p->type);
+		return 0;
+	}
+
+	*prop = *p;
+	if (!p->get(obj, prop)) {
+		return 0;
+	}
+
+	return 1;
+}
+
+int prop_set_property(struct lvm_property_type *p, void *obj,
+		struct lvm_property_type *prop,
+		unsigned type)
+{
+	while (p->id[0]) {
+		if (!strcmp(p->id, prop->id))
+			break;
+		p++;
+	}
+	if (!p->id[0]) {
+		log_errno(EINVAL, "Invalid property name %s", prop->id);
+		return 0;
+	}
+	if (!p->is_settable) {
+		log_errno(EINVAL, "Unable to set read-only property %s",
+			  prop->id);
+		return 0;
+	}
+	if (!(p->type & type)) {
+		log_errno(EINVAL, "Property name %s does not match type %d",
+			  prop->id, p->type);
+		return 0;
+	}
+
+	if (p->is_string)
+		p->value.string = prop->value.string;
+	else
+		p->value.integer = prop->value.integer;
+	if (!p->set(obj, p)) {
+		return 0;
+	}
+
+	return 1;
+}

lib/properties/prop_common.h

@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2013 Red Hat, Inc. All rights reserved.
+ *
+ * This file is part of LVM2.
+ *
+ * This copyrighted material is made available to anyone wishing to use,
+ * modify, copy, or redistribute it subject to the terms and conditions
+ * of the GNU Lesser General Public License v.2.1.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#ifndef _LVM_PROP_COMMON_H
+#define _LVM_PROP_COMMON_H
+
+#include <stdint.h>
+
+/*
+ * Common code for getting and setting properties.
+ */
+
+struct lvm_property_type {
+	unsigned type;
+	const char *id;
+	unsigned is_settable:1;
+	unsigned is_string:1;
+	unsigned is_integer:1;
+	union {
+		const char *string;
+		uint64_t integer;
+	} value;
+	int (*get) (const void *obj, struct lvm_property_type *prop);
+	int (*set) (void *obj, struct lvm_property_type *prop);
+};
+
+int prop_not_implemented_get(const void *obj, struct lvm_property_type *prop);
+int prop_not_implemented_set(void *obj, struct lvm_property_type *prop);
+
+int prop_get_property(struct lvm_property_type *p, const void *obj,
+		struct lvm_property_type *prop,
+		unsigned type);
+int prop_set_property(struct lvm_property_type *p, void *obj,
+		struct lvm_property_type *prop,
+		unsigned type);
+
+#define GET_NUM_PROPERTY_FN(NAME, VALUE, TYPE, VAR)			\
+static int _ ## NAME ## _get (const void *obj, struct lvm_property_type *prop) \
+{ \
+	const struct TYPE *VAR = (const struct TYPE *)obj; \
+\
+	prop->value.integer = VALUE; \
+	return 1; \
+}
+
+#define SET_NUM_PROPERTY_FN(NAME, SETFN, TYPE, VAR)			\
+static int _ ## NAME ## _set (void *obj, struct lvm_property_type *prop) \
+{ \
+	struct TYPE *VAR = (struct TYPE *)obj; \
+\
+	SETFN(VAR, prop->value.integer);		\
+	return 1; \
+}
+
+#define GET_STR_PROPERTY_FN(NAME, VALUE, TYPE, VAR)			\
+static int _ ## NAME ## _get (const void *obj, struct lvm_property_type *prop) \
+{ \
+	const struct TYPE *VAR = (const struct TYPE *)obj; \
+\
+	prop->value.string = (char *)VALUE;	\
+	return 1; \
+}
+
+/*
+ * The 'FIELD' macro arguments are defined as follows:
+ * 1. report_type.  An enum value that selects a specific
+ * struct dm_report_object_type in the _report_types array.  The value is
+ * used to select the containing base object address (see *obj_get*
+ * functions) for any data values of any field in the report.
+ * 2. Containing struct.  The structure that either contains the field data
+ * as a member or should be used to obtain the field data.  The containing
+ * struct should match the base object of the report_type.
+ * 3. Field type.  This must be either 'STR' or 'NUM'.
+ * 4. Report heading.  This is the field heading that is displayed by the
+ * reporting commands.
+ * 5. Data value pointer.  This argument is always a member of the
+ * containing struct.  It may point directly to the data value (for example,
+ * lv_uuid - see _uuid_disp()) or may be used to derive the data value (for
+ * example, seg_count - see _lvsegcount_disp()).  In the FIELD macro
+ * definition, it is used in an offset calculation to derive the offset to
+ * the data value from the containing struct base address.  Note that in some
+ * cases, the argument is the first member of the struct, in which case the
+ * data value pointer points to the start of the struct itself (for example,
+ * 'lvid' field of struct 'lv').
+ * 6. Minimum display width.  This is the minimum width used to display
+ * the field value, typically matching the width of the column heading.
+ * 7. Display function identifier.  Used to derive the full name of the
+ * function that displays this field.  Derivation is done by appending '_'
+ * then prepending this argument to '_disp'.  For example, if this argument
+ * is 'uuid', the display function is _uuid_disp().  Adding a new field may
+ * require defining a new display function (for example _myfieldname_disp()),
+ * or re-use of an existing one (for example, _uint32_disp()).
+ * 8. Unique format identifier / field id.  This name must be unique and is
+ * used to select fields via '-o' in the reporting commands (pvs/vgs/lvs).
+ * The string used to specify the field - the 'id' member of
+ * struct dm_report_field_type.
+ * 9. Description of field.  This is a brief (ideally <= 52 chars) description
+ * of the field used in the reporting commands.
+ * 10. Flags.
+ *     FIELD_MODIFIABLE.  A '_set' function exists to change the field's value.
+ *     The function name is derived in a similar way to item 7 above.
+ */
+
+#define STR 1
+#define NUM 2
+
+#define FIELD_MODIFIABLE 0x00000001
+#define FIELD(type, strct, field_type, head, field, width, fn, id, desc, settable) \
+	{ type, #id, settable, field_type == STR, field_type == NUM, { .integer = 0 }, _ ## id ## _get, _ ## id ## _set },
+
+#endif