From 3d1627daa7b62a30b8bb2d201829b1a6034e85be Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Fri, 14 Aug 2015 22:05:34 +0200
Subject: [PATCH] helper function for debugging

---
 src/include/taler_util.h | 24 ++++++++++++++++++++++++
 src/util/util.c          | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/src/include/taler_util.h b/src/include/taler_util.h
index 00397cc88..b6dd9596a 100644
--- a/src/include/taler_util.h
+++ b/src/include/taler_util.h
@@ -73,6 +73,30 @@ void
 TALER_gcrypt_init (void);
 
 
+/**
+ * Convert a buffer to an 8-character string
+ * representative of the contents. This is used
+ * for logging binary data when debugging.
+ *
+ * @param buf buffer to log
+ * @param buf_size number of bytes in @a buf
+ * @return text representation of buf, valid until next
+ *         call to this function
+ */
+const char *
+TALER_b2s (const void *buf,
+	   size_t buf_size);
+
+/**
+ * Convert a fixed-sized object to a string using
+ * #TALER_b2s().
+ *
+ * @param obj address of object to convert
+ * @return string representing the binary obj buffer
+ */
+#define TALER_B2S(obj) TALER_b2s (obj, sizeof (*obj))
+
+
 /**
  * Round a time value so that it is suitable for transmission
  * via JSON encodings.
diff --git a/src/util/util.c b/src/util/util.c
index f45598b0c..08438cfab 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -27,6 +27,38 @@
 #include <gcrypt.h>
 
 
+/**
+ * Convert a buffer to an 8-character string
+ * representative of the contents. This is used
+ * for logging binary data when debugging.
+ *
+ * @param buf buffer to log
+ * @param buf_size number of bytes in @a buf
+ * @return text representation of buf, valid until next
+ *         call to this function
+ */
+const char *
+TALER_b2s (const void *buf,
+	   size_t buf_size)
+{
+  static char ret[9];
+  struct GNUNET_HashCode hc;
+  char *tmp;
+
+  GNUNET_CRYPTO_hash (buf,
+		      buf_size,
+		      &hc);
+  tmp = GNUNET_STRINGS_data_to_string_alloc (&hc,
+					     sizeof (hc));
+  memcpy (ret,
+	  tmp,
+	  8);
+  GNUNET_free (tmp);
+  ret[8] = '\0';
+  return ret;
+}	   
+
+
 /**
  * Obtain denomination amount from configuration file.
  *