[libgda: 2/5] improve geometric point support

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit db6bae8a26a180978fed568e422e6df78b6302e7
Author: taozuhong <taozuhong gmail com>
Date:   Thu Sep 30 17:02:25 2021 +0800

    improve geometric point support

 libgda/gda-value.c                    | 21 ++++++++++
 providers/mysql/gda-mysql-recordset.c | 73 ++++++++++++++++++++++++++++++++++-
 2 files changed, 93 insertions(+), 1 deletion(-)
---
diff --git a/libgda/gda-value.c b/libgda/gda-value.c
index a68f9f72c..e7b87d1ea 100644
--- a/libgda/gda-value.c
+++ b/libgda/gda-value.c
@@ -192,6 +192,18 @@ set_from_string (GValue *value, const gchar *as_string)
                        retval = TRUE;
                }
        }
+       else if (type == GDA_TYPE_GEOMETRIC_POINT) {
+               GdaGeometricPoint* point = gda_geometric_point_new ();
+               as_string++;
+               gda_geometric_point_set_x (point, g_ascii_strtod (as_string, NULL));
+               as_string = strchr (as_string, ',');
+               as_string++;
+               gda_geometric_point_set_y (point, g_ascii_strtod (as_string, NULL));
+               
+               gda_value_set_geometric_point (value, point);
+               gda_geometric_point_free (point);
+               retval = TRUE;
+       }
        else if (type == GDA_TYPE_NUMERIC) {
                GdaNumeric *numeric = gda_numeric_new ();
                gda_numeric_set_from_string (numeric, as_string);
@@ -2748,6 +2760,15 @@ gda_value_stringify (const GValue *value)
                else
                        return g_strdup ("NULL");
        }
+       else if (g_type_is_a (type, GDA_TYPE_GEOMETRIC_POINT)) {
+               GdaGeometricPoint* point;
+               point = (GdaGeometricPoint*) g_value_get_boxed (value);
+               if (point != NULL) {
+                       return g_strdup_printf ("(%.*g,%.*g)", DBL_DIG, point->x, DBL_DIG, point->y);
+               } else {
+                       return "NULL";
+               }
+       }
   else if (g_type_is_a (type, GDA_TYPE_TIME)) {
                GdaTime *gts;
                gts = (GdaTime*) g_value_get_boxed (value);
diff --git a/providers/mysql/gda-mysql-recordset.c b/providers/mysql/gda-mysql-recordset.c
index 7aea2fd1e..41917a544 100644
--- a/providers/mysql/gda-mysql-recordset.c
+++ b/providers/mysql/gda-mysql-recordset.c
@@ -278,6 +278,60 @@ gda_mysql_recordset_dispose (GObject  *object)
        G_OBJECT_CLASS (gda_mysql_recordset_parent_class)->dispose (object);
 }
 
+/**
+ * Read a long from a byte buffer in big endian format.
+ * @param buf must be 8 bytes
+ */
+static gint64 read_long_from_bytes_big_endian(const guchar* buf) {
+       return  (gint64) (buf[0] & 0xff) << 56
+                       | (gint64) (buf[1] & 0xff) << 48
+                       | (gint64) (buf[2] & 0xff) << 40
+                       | (gint64) (buf[3] & 0xff) << 32
+                       | (gint64) (buf[4] & 0xff) << 24
+                       | (gint64) (buf[5] & 0xff) << 16
+                       | (gint64) (buf[6] & 0xff) <<  8
+                       | (gint64) (buf[7] & 0xff);
+}
+/**
+ * Read a long from a byte buffer in little endian format.
+ * @param buf must be 8 bytes
+ */
+static gint64 read_long_from_bytes_little_endian(const guchar* buf) {
+       return  (gint64) (buf[7] & 0xff) << 56
+                       | (gint64) (buf[6] & 0xff) << 48
+                       | (gint64) (buf[5] & 0xff) << 40
+                       | (gint64) (buf[4] & 0xff) << 32
+                       | (gint64) (buf[3] & 0xff) << 24
+                       | (gint64) (buf[2] & 0xff) << 16
+                       | (gint64) (buf[1] & 0xff) <<  8
+                       | (gint64) (buf[0] & 0xff);
+}
+/**
+ * Read a long from a byte buffer in big or little endian format.
+ * @param bigEndian true for big endian, false for little endian
+ * @param buf must be 8 bytes
+ */
+static gdouble read_double_from_bytes(const guchar* buf, gboolean big_endian) {
+    gint64 long_val =  big_endian ? read_long_from_bytes_big_endian (buf)
+            : read_long_from_bytes_little_endian (buf);
+       union {
+        gint64 val_long;
+        gdouble val_double;
+    } val_union;
+    val_union.val_long = long_val;
+
+    return (gdouble)val_union.val_double;
+}
+
+/**
+* Read a long from a byte buffer in big or little endian format.
+* @param bigEndian true for big endian, false for little endian
+* @param buf must be 8 bytes length after offset
+*/
+static double read_double_from_bytes_offset(const guchar* buf, gint offset, gboolean big_endian) {
+       return read_double_from_bytes(buf + offset, big_endian);
+}
+
 /*
  * Public functions
  */
@@ -305,6 +359,9 @@ _gda_mysql_type_to_gda (G_GNUC_UNUSED MysqlConnectionData *cdata,
        case MYSQL_TYPE_NEWDECIMAL:
                gtype = GDA_TYPE_NUMERIC;
                break;
+       case MYSQL_TYPE_GEOMETRY:
+               gtype = GDA_TYPE_GEOMETRIC_POINT;
+               break;
        case MYSQL_TYPE_DOUBLE:
                gtype = G_TYPE_DOUBLE;
                break;
@@ -325,7 +382,6 @@ _gda_mysql_type_to_gda (G_GNUC_UNUSED MysqlConnectionData *cdata,
        case MYSQL_TYPE_VAR_STRING:
        case MYSQL_TYPE_SET:
        case MYSQL_TYPE_ENUM:
-       case MYSQL_TYPE_GEOMETRY:
        case MYSQL_TYPE_BIT:
        case MYSQL_TYPE_BLOB:
        default:
@@ -949,6 +1005,21 @@ new_row_from_mysql_stmt (GdaMysqlRecordset *imodel, G_GNUC_UNUSED gint rownum, G
                                        gda_numeric_free (numeric);
                                }
                        }
+                       else if (type == GDA_TYPE_GEOMETRIC_POINT) {
+                               if (length > 0) {
+                                       GdaGeometricPoint* point = gda_geometric_point_new ();
+
+                                       guchar bytes = (guchar)(*(bvalue + 4));
+                                       gboolean is_big_endian = (0 == bytes);
+                                       gdouble x = read_double_from_bytes_offset(bvalue, 9, is_big_endian);
+                                       gdouble y = read_double_from_bytes_offset(bvalue, 17, is_big_endian);
+                                       gda_geometric_point_set_x (point, x);
+                                       gda_geometric_point_set_y (point, y);
+                                       gda_value_set_geometric_point (value, point);
+                                       // g_warning("Point: %s", gda_value_stringify(value));
+                                       gda_geometric_point_free (point);
+                               }
+                       }
                        else if (type == G_TYPE_DOUBLE) {
                                if (length > 0)
                                        g_value_set_double (value, g_ascii_strtod (bvalue, NULL));