Add support for preprocessed JSON strings (with optimizations) in encoder

In some situations, you may have a large python dictionary you need to JSONify but one of the values inside the dict is already a JSON string. This is common when pulling an object from a database, for example, where one of the fields is a JSON blob/string. Previously you would have to deserialize and then reserialize that string just to serialize the high level object, but obviously this is unnecessarily slow. This changes adds a method/type that can be used to wrap a str and tell the serializer to just pass it through instead.

1 files changed, 22 insertions, 0 deletions

diff --git a/simplejson/_speedups.c b/simplejson/_speedups.c
index 9976464..2d81063 100644
--- a/simplejson/_speedups.c
+++ b/simplejson/_speedups.c
@@ -245,6 +245,8 @@ static void
 encoder_dealloc(PyObject *self);
 static int
 encoder_clear(PyObject *self);
+static int
+is_raw_json(PyObject *obj);
 static PyObject *
 encoder_stringify_key(PyEncoderObject *s, PyObject *key);
 static int
@@ -277,6 +279,20 @@ moduleinit(void);
 
 #define MIN_EXPANSION 6
 
+static PyObject* RawJSONType;
+static int
+is_raw_json(PyObject *obj)
+{
+    if (RawJSONType == NULL) {
+        PyObject *encoder_module = PyImport_ImportModule("simplejson.encoder");
+        RawJSONType = PyObject_GetAttrString(encoder_module, "RawJSON");
+        Py_DECREF(encoder_module);
+        if (RawJSONType == NULL)
+            return 0;
+    }
+    return PyObject_IsInstance(obj, RawJSONType) ? 1 : 0;
+}
+
 static int
 JSON_Accu_Init(JSON_Accu *acc)
 {
@@ -2868,6 +2884,12 @@ encoder_listencode_obj(PyEncoderObject *s, JSON_Accu *rval, PyObject *obj, Py_ss
             if (encoded != NULL)
                 rv = _steal_accumulate(rval, encoded);
         }
+        else if (is_raw_json(obj))
+        {
+            PyObject *encoded = PyObject_GetAttrString(obj, "encoded_json");
+            if (encoded != NULL)
+                rv = _steal_accumulate(rval, encoded);
+        }
         else if (PyInt_Check(obj) || PyLong_Check(obj)) {
             PyObject *encoded;
             if (PyInt_CheckExact(obj) || PyLong_CheckExact(obj)) {