qapi: Add human mode to StringOutputVisitor

This will be used by "info qtree".  For numbers it prints both the
decimal and hex values.  For sizes it rounds to the nearest power
of 2^10.  For strings, it puts quotes around the string and separates
NULL and empty string.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>

1 files changed, 52 insertions, 3 deletions

diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c
index 921653d..67a8798 100644
--- a/qapi/string-output-visitor.c
+++ b/qapi/string-output-visitor.c
@@ -14,10 +14,12 @@
 #include "qapi/string-output-visitor.h"
 #include "qapi/visitor-impl.h"
 #include "qapi/qmp/qerror.h"
+#include "qemu/host-utils.h"
 
 struct StringOutputVisitor
 {
     Visitor visitor;
+    bool human;
     char *string;
 };
 
@@ -31,7 +33,45 @@ static void print_type_int(Visitor *v, int64_t *obj, const char *name,
                            Error **errp)
 {
     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
-    string_output_set(sov, g_strdup_printf("%lld", (long long) *obj));
+    char *out;
+
+    if (sov->human) {
+        out = g_strdup_printf("%lld (%#llx)", (long long) *obj, (long long) *obj);
+    } else {
+        out = g_strdup_printf("%lld", (long long) *obj);
+    }
+    string_output_set(sov, out);
+}
+
+static void print_type_size(Visitor *v, uint64_t *obj, const char *name,
+                           Error **errp)
+{
+    StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
+    static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T' };
+    uint64_t div, val;
+    char *out;
+    int i;
+
+    if (!sov->human) {
+        out = g_strdup_printf("%llu", (long long) *obj);
+        string_output_set(sov, out);
+        return;
+    }
+
+    val = *obj;
+
+    /* Compute floor(log2(val)).  */
+    i = 64 - clz64(val);
+
+    /* Find the power of 1024 that we'll display as the units.  */
+    i /= 10;
+    if (i >= ARRAY_SIZE(suffixes)) {
+        i = ARRAY_SIZE(suffixes) - 1;
+    }
+    div = 1ULL << (i * 10);
+
+    out = g_strdup_printf("%0.03f%c", (double)val/div, suffixes[i]);
+    string_output_set(sov, out);
 }
 
 static void print_type_bool(Visitor *v, bool *obj, const char *name,
@@ -45,7 +85,14 @@ static void print_type_str(Visitor *v, char **obj, const char *name,
                            Error **errp)
 {
     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
-    string_output_set(sov, g_strdup(*obj ? *obj : ""));
+    char *out;
+
+    if (sov->human) {
+        out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
+    } else {
+        out = g_strdup(*obj ? *obj : "");
+    }
+    string_output_set(sov, out);
 }
 
 static void print_type_number(Visitor *v, double *obj, const char *name,
@@ -73,14 +120,16 @@ void string_output_visitor_cleanup(StringOutputVisitor *sov)
     g_free(sov);
 }
 
-StringOutputVisitor *string_output_visitor_new(void)
+StringOutputVisitor *string_output_visitor_new(bool human)
 {
     StringOutputVisitor *v;
 
     v = g_malloc0(sizeof(*v));
 
+    v->human = human;
     v->visitor.type_enum = output_type_enum;
     v->visitor.type_int = print_type_int;
+    v->visitor.type_size = print_type_size;
     v->visitor.type_bool = print_type_bool;
     v->visitor.type_str = print_type_str;
     v->visitor.type_number = print_type_number;