data: Let sdb_data_format() return the number of bytes written.

[sysdb.git] / src / include / core / data.h

diff --git a/src/include/core/data.h b/src/include/core/data.h
index b657486b794b16cdb9bc00560cb0b2f4ab2090dc..230c1c9f887cd434b7c34bd74edf72ec12b88a5d 100644 (file)
--- a/src/include/core/data.h
+++ b/src/include/core/data.h
@@ -45,13 +45,22 @@ enum {
        SDB_TYPE_BINARY,
 };
 
+#define SDB_TYPE_TO_STRING(t) \
+       (((t) == SDB_TYPE_INTEGER) \
+               ? "INTEGER" \
+               : ((t) == SDB_TYPE_DECIMAL) \
+                       ? "DECIMAL" \
+                       : ((t) == SDB_TYPE_STRING) \
+                               ? "STRING" \
+                               : ((t) == SDB_TYPE_DATETIME) \
+                                       ? "DATETIME" \
+                                       : ((t) == SDB_TYPE_BINARY) \
+                                               ? "BINARY" \
+                                               : "UNKNOWN")
+
 /*
  * sdb_data_t:
  * A datum retrieved from an arbitrary data source.
- *
- * The string and binary objects are managed by whoever creates the data
- * object, thus, they must not be freed or modified. If you want to keep them,
- * make sure to make a copy.
  */
 typedef struct {
        int type;
@@ -67,6 +76,55 @@ typedef struct {
        } data;
 } sdb_data_t;
 
+/*
+ * sdb_data_copy:
+ * Copy the datum stored in 'src' to the memory location pointed to by 'dst'.
+ * Any dynamic data (strings, binary data) is copied to newly allocated
+ * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory
+ * stored in a datum.
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src);
+
+/*
+ * sdb_data_free_datum:
+ * Free any dynamic memory referenced by the specified datum. Does not free
+ * the memory allocated for the sdb_data_t object itself. This function must
+ * not be used if any static or stack memory is referenced from the data
+ * object.
+ */
+void
+sdb_data_free_datum(sdb_data_t *datum);
+
+/*
+ * sdb_data_strlen:
+ * Returns a (worst-case) estimate for the number of bytes required to format
+ * the datum as a string. Does not take the terminating null byte into
+ * account.
+ */
+size_t
+sdb_data_strlen(sdb_data_t *datum);
+
+/*
+ * sdb_data_format:
+ * Output the specified datum to the specified string using a default format.
+ * If the buffer size is less than the return value of sdb_data_strlen, the
+ * datum may be truncated. The buffer will always be nul-terminated after
+ * calling this function.
+ *
+ * Returns:
+ *  - the number of characters written to the buffer (excluding the terminated
+ *    null byte) or the number of characters which would have been written in
+ *    case the output was truncated
+ *  - a negative value else
+ */
+int
+sdb_data_format(sdb_data_t *datum, char *buf, size_t buflen);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif