New "tag data" container struct + some basic methods to deal with it

- to be used for passing around header and extension data
- inspired by similar changes in rpm5.org, details and implementation differ

Makefile.am

@@ -65,6 +65,7 @@ pkginclude_HEADERS += lib/rpmfi.h
 pkginclude_HEADERS += lib/rpmgi.h
 pkginclude_HEADERS += lib/rpmps.h
 pkginclude_HEADERS += lib/rpmtag.h
+pkginclude_HEADERS += lib/rpmtd.h
 pkginclude_HEADERS += lib/rpmte.h
 pkginclude_HEADERS += lib/rpmts.h
 pkginclude_HEADERS += lib/rpmtypes.h

lib/Makefile.am

@@ -24,7 +24,7 @@ librpm_la_SOURCES = \
 	backend/dbconfig.c backend/db3.c \
 	hdrNVR.c header.c headerfmt.c header_internal.c header_internal.h \
 	poptDB.c rpmhash.c rpmhash.h rpmdb.c rpmdb_internal.h \
-	fprint.c fprint.h tagname.c tagtbl.c \
+	fprint.c fprint.h tagname.c tagtbl.c rpmtd.c \
 	cpio.c cpio.h depends.c formats.c fs.c fsm.c fsm.h \
 	manifest.c manifest.h misc.c package.c \
 	poptALL.c poptI.c poptQV.c psm.c psm.h query.c \

lib/header.h

@@ -14,6 +14,7 @@
 
 #include <rpm/rpmio.h>
 #include <rpm/rpmtypes.h>
+#include <rpm/rpmtd.h>
 #include <rpm/rpmutil.h>
 
 #ifdef __cplusplus

lib/rpmtd.c

@@ -0,0 +1,47 @@
+#include "system.h"
+
+#include <rpm/rpmtd.h>
+#include <rpm/rpmstring.h>
+
+#include "debug.h"
+
+rpmtd rpmtdNew(void)
+{
+    rpmtd td = xmalloc(sizeof(*td));
+    rpmtdReset(td);
+    return td;
+}
+
+rpmtd rpmtdFree(rpmtd td)
+{
+    /* permit free on NULL td */
+    if (td != NULL) {
+	/* XXX should we free data too - a flag maybe? */
+	free(td);
+    }
+    return NULL;
+}
+
+void rpmtdReset(rpmtd td)
+{
+    assert(td != NULL);
+
+    memset(td, 0, sizeof(*td));
+    td->ix = -1;
+}
+
+void rpmtdFreeData(rpmtd td)
+{
+    assert(td != NULL);
+
+    if (td->freeData) {
+	free(td->data);
+    }
+    rpmtdReset(td);
+}
+
+rpm_count_t rpmtdCount(rpmtd td)
+{
+    assert(td != NULL);
+    return td->count;
+}

lib/rpmtd.h

@@ -0,0 +1,52 @@
+#ifndef _RPMTD_H
+#define _RPMTD_H
+
+#include <rpm/rpmtypes.h>
+
+/** \ingroup rpmtd
+ * Container for rpm tag data (from headers or extensions).
+ */
+struct rpmtd_s {
+    rpmTag tag;		/* rpm tag of this data entry*/
+    rpmTagType type;	/* data type */
+    rpm_count_t count;	/* number of entries */
+    rpm_data_t data;	/* pointer to actual data */
+    int freeData;	/* was data malloced */
+    int ix;		/* iteration index */
+};
+
+/** \ingroup rpmtd
+ * Create new tag data container
+ * ®return		New, initialized tag data container.
+ */
+rpmtd rpmtdNew(void);
+
+/** \ingroup rpmtd
+ * Destroy tag data container.
+ * @param td		Tag data container
+ * @return		NULL always
+ */
+rpmtd rpmtdFree(rpmtd td);
+ 
+/** \ingroup rpmtd
+ * (Re-)initialize tag data container. Contents will be zeroed out
+ * and iteration index reset.
+ * @param td		Tag data container
+ */
+void rpmtdReset(rpmtd td);
+
+/** \ingroup rpmtd
+ * Free contained data. This is always safe to call as the container knows 
+ * if data was malloc'ed or not. Container is reinitialized.
+ * @param td		Tag data container
+ */
+void rpmtdFreeData(rpmtd td);
+
+/** \ingroup rpmtd
+ * Retrieve number of entries in the container.
+ * @param td		Tag data container
+ * @return		Number of entries in contained data.
+ */
+rpm_count_t rpmtdCount(rpmtd td);
+
+#endif /* _RPMTD_H */

lib/rpmtypes.h

@@ -32,6 +32,8 @@ typedef uint32_t	rpm_count_t;
 typedef void *		rpm_data_t;
 typedef const void *	rpm_constdata_t;
 
+typedef struct rpmtd_s * rpmtd;
+
 typedef uint32_t	rpm_color_t;
 typedef uint32_t	rpm_flag_t;
 typedef int32_t		rpm_tid_t;

preinstall.am

@@ -90,6 +90,10 @@ include/rpm/rpmtag.h: lib/rpmtag.h include/rpm/$(dirstamp)
 	$(INSTALL_DATA) $(top_srcdir)/lib/rpmtag.h include/rpm/rpmtag.h
 BUILT_SOURCES += include/rpm/rpmtag.h
 CLEANFILES += include/rpm/rpmtag.h
+include/rpm/rpmtd.h: lib/rpmtd.h include/rpm/$(dirstamp)
+	$(INSTALL_DATA) $(top_srcdir)/lib/rpmtd.h include/rpm/rpmtd.h
+BUILT_SOURCES += include/rpm/rpmtd.h
+CLEANFILES += include/rpm/rpmtd.h
 include/rpm/rpmte.h: lib/rpmte.h include/rpm/$(dirstamp)
 	$(INSTALL_DATA) $(top_srcdir)/lib/rpmte.h include/rpm/rpmte.h
 BUILT_SOURCES += include/rpm/rpmte.h