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

[sysdb.git] / src / core / data.c

diff --git a/src/core/data.c b/src/core/data.c
index 54b6d282e6640d755e38457e4dbd497bb995fd32..bf1f55ec8a1f053c2fce945e3ba161b1ea16eeaa 100644 (file)
--- a/src/core/data.c
+++ b/src/core/data.c
@@ -29,6 +29,7 @@
 
 #include <inttypes.h>
 
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -85,25 +86,53 @@ sdb_data_free_datum(sdb_data_t *datum)
        }
 } /* sdb_data_free_datum */
 
+size_t
+sdb_data_strlen(sdb_data_t *datum)
+{
+       if (! datum)
+               return 0;
+
+       switch (datum->type) {
+               case SDB_TYPE_INTEGER:
+                       /* log(64) */
+                       return 20;
+               case SDB_TYPE_DECIMAL:
+                       /* XXX: -0xN.NNNNNNp+NNN */
+                       return 42;
+               case SDB_TYPE_STRING:
+                       if (! datum->data.string)
+                               return 6; /* "NULL" */
+                       /* in the worst case, each character needs to be escaped */
+                       return 2 * strlen(datum->data.string) + 2;
+               case SDB_TYPE_DATETIME:
+                       /* "YYYY-MM-DD HH:MM:SS +zzzz" */
+                       return 27;
+               case SDB_TYPE_BINARY:
+                       /* "\xNN" */
+                       return 4 * datum->data.binary.length + 2;
+       }
+       return 0;
+} /* sdb_data_strlen */
+
 int
-sdb_data_format(sdb_data_t *datum, sdb_strbuf_t *buf)
+sdb_data_format(sdb_data_t *datum, char *buf, size_t buflen)
 {
+       int ret = -1;
+
        if ((! datum) || (! buf))
                return -1;
 
        switch (datum->type) {
                case SDB_TYPE_INTEGER:
-                       sdb_strbuf_append(buf, "%"PRIi64, datum->data.integer);
+                       ret = snprintf(buf, buflen, "%"PRIi64, datum->data.integer);
                        break;
                case SDB_TYPE_DECIMAL:
-                       sdb_strbuf_append(buf, "%a", datum->data.decimal);
+                       ret = snprintf(buf, buflen, "%a", datum->data.decimal);
                        break;
                case SDB_TYPE_STRING:
-                       if (! datum->data.string) {
-                               sdb_strbuf_append(buf, "\"NULL\"");
-                               return 0;
-                       }
-                       {
+                       if (! datum->data.string)
+                               ret = snprintf(buf, buflen, "\"NULL\"");
+                       else {
                                char tmp[2 * strlen(datum->data.string) + 1];
                                size_t i, pos;
 
@@ -119,7 +148,7 @@ sdb_data_format(sdb_data_t *datum, sdb_strbuf_t *buf)
                                        ++pos;
                                }
                                tmp[pos] = '\0';
-                               sdb_strbuf_append(buf, "\"%s\"", tmp);
+                               ret = snprintf(buf, buflen, "\"%s\"", tmp);
                        }
                        break;
                case SDB_TYPE_DATETIME:
@@ -129,7 +158,7 @@ sdb_data_format(sdb_data_t *datum, sdb_strbuf_t *buf)
                                                        datum->data.datetime))
                                        return -1;
                                tmp[sizeof(tmp) - 1] = '\0';
-                               sdb_strbuf_append(buf, "\"%s\"", tmp);
+                               ret = snprintf(buf, buflen, "\"%s\"", tmp);
                        }
                        break;
                case SDB_TYPE_BINARY:
@@ -155,13 +184,12 @@ sdb_data_format(sdb_data_t *datum, sdb_strbuf_t *buf)
                                        ++pos;
                                }
                                tmp[pos] = '\0';
-                               sdb_strbuf_append(buf, "\"%s\"", tmp);
+                               ret = snprintf(buf, buflen, "\"%s\"", tmp);
                        }
                        break;
-               default:
-                       return -1;
        }
-       return 0;
+       buf[buflen - 1] = '\0';
+       return ret;
 } /* sdb_data_format */
 
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */