Large object mode parsing refactored

Added parsing of text/binary mode.

5 files changed, 146 insertions, 61 deletions

diff --git a/psycopg/connection_type.c b/psycopg/connection_type.c
index c947850..ae92d68 100644
--- a/psycopg/connection_type.c
+++ b/psycopg/connection_type.c
@@ -514,15 +514,16 @@ static PyObject *
 psyco_conn_lobject(connectionObject *self, PyObject *args, PyObject *keywds)
 {
     Oid oid=InvalidOid, new_oid=InvalidOid;
-    char *smode = NULL, *new_file = NULL;
-    int mode=0;
-    PyObject *obj, *factory = NULL;
+    char *new_file = NULL;
+    const char *smode = "";
+    PyObject *factory = (PyObject *)&lobjectType;
+    PyObject *obj;
 
     static char *kwlist[] = {"oid", "mode", "new_oid", "new_file",
                              "cursor_factory", NULL};
-    
+
     if (!PyArg_ParseTupleAndKeywords(args, keywds, "|izizO", kwlist,
-                                     &oid, &smode, &new_oid, &new_file, 
+                                     &oid, &smode, &new_oid, &new_file,
                                      &factory)) {
         return NULL;
     }
@@ -537,33 +538,13 @@ psyco_conn_lobject(connectionObject *self, PyObject *args, PyObject *keywds)
             oid, smode);
     Dprintf("psyco_conn_lobject:     parameters: new_oid = %d, new_file = %s",
             new_oid, new_file);
-    
-    /* build a mode number out of the mode string: right now we only accept
-       'r', 'w' and 'rw' (but note that 'w' implies 'rw' because PostgreSQL
-       backend does that. */
-    if (smode) {
-        if (strncmp("rw", smode, 2) == 0)
-            mode = INV_READ+INV_WRITE;
-        else if (smode[0] == 'r')
-           mode = INV_READ;
-        else if (smode[0] == 'w')
-           mode = INV_WRITE;
-        else if (smode[0] == 'n')
-           mode = -1;
-        else {
-            PyErr_SetString(PyExc_TypeError,
-                "mode should be one of 'r', 'w' or 'rw'");
-            return NULL;
-        }
-    }
 
-    if (factory == NULL) factory = (PyObject *)&lobjectType;
     if (new_file)
-        obj = PyObject_CallFunction(factory, "Oiiis", 
-            self, oid, mode, new_oid, new_file);
+        obj = PyObject_CallFunction(factory, "Oisis",
+            self, oid, smode, new_oid, new_file);
     else
-        obj = PyObject_CallFunction(factory, "Oiii",
-            self, oid, mode, new_oid);
+        obj = PyObject_CallFunction(factory, "Oisi",
+            self, oid, smode, new_oid);
 
     if (obj == NULL) return NULL;
     if (PyObject_IsInstance(obj, (PyObject *)&lobjectType) == 0) {
@@ -572,7 +553,7 @@ psyco_conn_lobject(connectionObject *self, PyObject *args, PyObject *keywds)
         Py_DECREF(obj);
         return NULL;
     }
-    
+
     Dprintf("psyco_conn_lobject: new lobject at %p: refcnt = "
             FORMAT_CODE_PY_SSIZE_T,
             obj, Py_REFCNT(obj));
diff --git a/psycopg/lobject.h b/psycopg/lobject.h
index cddfa6e..293f608 100644
--- a/psycopg/lobject.h
+++ b/psycopg/lobject.h
@@ -42,7 +42,8 @@ typedef struct {
     connectionObject *conn;  /* connection owning the lobject */
     long int mark;           /* copied from conn->mark */
 
-    const char *smode;       /* string mode if lobject was opened */
+    char *smode;             /* string mode if lobject was opened */
+    int mode;                /* numeric version of smode */
 
     int fd;                  /* the file descriptor for file-like ops */
     Oid oid;                 /* the oid for this lobject */
@@ -51,7 +52,7 @@ typedef struct {
 /* functions exported from lobject_int.c */
 
 HIDDEN int lobject_open(lobjectObject *self, connectionObject *conn,
-                        Oid oid, int mode, Oid new_oid,
+                        Oid oid, const char *smode, Oid new_oid,
                         const char *new_file);
 HIDDEN int lobject_unlink(lobjectObject *self);
 HIDDEN int lobject_export(lobjectObject *self, const char *filename);
@@ -87,6 +88,12 @@ if (self->conn->mark != self->mark) {                  \
     return NULL;                                       \
 }
 
+/* Values for the lobject mode */
+#define LOBJECT_READ  1
+#define LOBJECT_WRITE 2
+#define LOBJECT_BINARY 4
+#define LOBJECT_TEXT 8
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/psycopg/lobject_int.c b/psycopg/lobject_int.c
index 6ee3ecf..252d1c9 100644
--- a/psycopg/lobject_int.c
+++ b/psycopg/lobject_int.c
@@ -43,15 +43,118 @@ collect_error(connectionObject *conn, char **error)
         *error = strdup(msg);
 }
 
+
+/* Check if the mode passed to the large object is valid.
+ * In case of success return a value >= 0
+ * On error return a value < 0 and set an exception.
+ *
+ * Valid mode are [r|w|rw|n][t|b]
+ */
+static int
+_lobject_parse_mode(const char *mode)
+{
+    int rv = 0;
+    size_t pos = 0;
+
+    if (0 == strncmp("rw", mode, 2)) {
+        rv |= LOBJECT_READ | LOBJECT_WRITE;
+        pos += 2;
+    }
+    else {
+        switch (mode[0]) {
+        case 'r':
+            rv |= LOBJECT_READ;
+            pos += 1;
+            break;
+        case 'w':
+            rv |= LOBJECT_WRITE;
+            pos += 1;
+            break;
+        case 'n':
+            pos += 1;
+            break;
+        default:
+            rv |= LOBJECT_READ;
+            break;
+        }
+    }
+
+    switch (mode[pos]) {
+        case 't':
+            rv |= LOBJECT_TEXT;
+            pos += 1;
+            break;
+        case 'b':
+            rv |= LOBJECT_BINARY;
+            pos += 1;
+            break;
+        default:
+#if PY_MAJOR_VERSION < 3
+            rv |= LOBJECT_BINARY;
+#else
+            rv |= LOBJECT_TEXT;
+#endif
+            break;
+    }
+
+    if (pos != strlen(mode)) {
+        PyErr_Format(PyExc_ValueError,
+            "bad mode for lobject: '%s'", mode);
+        rv = -1;
+    }
+
+    return rv;
+}
+
+
+/* Return a string representing the lobject mode.
+ *
+ * The return value is a new string allocated on the Python heap.
+ */
+static char *
+_lobject_unparse_mode(int mode)
+{
+    char *buf;
+    char *c;
+
+    /* the longest is 'rwt' */
+    c = buf = PyMem_Malloc(4);
+
+    if (mode & LOBJECT_READ) { *c++ = 'r'; }
+    if (mode & LOBJECT_WRITE) { *c++ = 'w'; }
+
+    if (buf == c) {
+        /* neither read nor write */
+        *c++ = 'n';
+    }
+    else {
+        if (mode & LOBJECT_TEXT) {
+            *c++ = 't';
+        }
+        else {
+            *c++ = 'b';
+        }
+    }
+    *c = '\0';
+
+    return buf;
+}
+
 /* lobject_open - create a new/open an existing lo */
 
 int
 lobject_open(lobjectObject *self, connectionObject *conn,
-              Oid oid, int mode, Oid new_oid, const char *new_file)
+              Oid oid, const char *smode, Oid new_oid, const char *new_file)
 {
     int retvalue = -1;
     PGresult *pgres = NULL;
     char *error = NULL;
+    int pgmode = 0;
+    int mode;
+
+    if (0 > (mode = _lobject_parse_mode(smode))) {
+        return -1;
+    }
 
     Py_BEGIN_ALLOW_THREADS;
     pthread_mutex_lock(&(self->conn->lock));
@@ -78,19 +181,19 @@ lobject_open(lobjectObject *self, connectionObject *conn,
             goto end;
         }
 
-        mode = INV_WRITE;
+        mode = (mode & ~LOBJECT_READ) | LOBJECT_WRITE;
     }
     else {
         self->oid = oid;
-        if (mode == 0) mode = INV_READ;
     }
 
-    /* if the oid is a real one we try to open with the given mode,
-       unless the mode is -1, meaning "don't open!" */
-    if (mode != -1) {
-        self->fd = lo_open(self->conn->pgconn, self->oid, mode);
-        Dprintf("lobject_open: large object opened with fd = %d",
-            self->fd);
+    /* if the oid is a real one we try to open with the given mode */
+    if (mode & LOBJECT_READ) { pgmode |= INV_READ; }
+    if (mode & LOBJECT_WRITE) { pgmode |= INV_WRITE; }
+    if (pgmode) {
+        self->fd = lo_open(self->conn->pgconn, self->oid, pgmode);
+        Dprintf("lobject_open: large object opened with mode = %i fd = %d",
+            pgmode, self->fd);
 
         if (self->fd == -1) {
             collect_error(self->conn, &error);
@@ -98,17 +201,10 @@ lobject_open(lobjectObject *self, connectionObject *conn,
             goto end;
         }
     }
+
     /* set the mode for future reference */
-    switch (mode) {
-    case -1:
-        self->smode = "n"; break;
-    case INV_READ:
-        self->smode = "r"; break;
-    case INV_WRITE:
-        self->smode = "w"; break;
-    case INV_READ+INV_WRITE:
-        self->smode = "rw"; break;
-    }
+    self->mode = mode;
+    self->smode = _lobject_unparse_mode(mode);
     retvalue = 0;
 
  end:
diff --git a/psycopg/lobject_type.c b/psycopg/lobject_type.c
index 9a5fb0b..4c9e2ae 100644
--- a/psycopg/lobject_type.c
+++ b/psycopg/lobject_type.c
@@ -277,7 +277,7 @@ static struct PyMemberDef lobjectObject_members[] = {
     {"oid", T_UINT, offsetof(lobjectObject, oid), READONLY,
         "The backend OID associated to this lobject."},
     {"mode", T_STRING, offsetof(lobjectObject, smode), READONLY,
-        "Open mode ('r', 'w', 'rw' or 'n')."},
+        "Open mode."},
     {NULL}
 };
 
@@ -293,7 +293,7 @@ static struct PyGetSetDef lobjectObject_getsets[] = {
 
 static int
 lobject_setup(lobjectObject *self, connectionObject *conn,
-              Oid oid, int mode, Oid new_oid, const char *new_file)
+              Oid oid, const char *smode, Oid new_oid, const char *new_file)
 {
     Dprintf("lobject_setup: init lobject object at %p", self);
 
@@ -311,7 +311,7 @@ lobject_setup(lobjectObject *self, connectionObject *conn,
     self->fd = -1;
     self->oid = InvalidOid;
 
-    if (lobject_open(self, conn, oid, mode, new_oid, new_file) == -1)
+    if (lobject_open(self, conn, oid, smode, new_oid, new_file) == -1)
         return -1;
 
    Dprintf("lobject_setup: good lobject object at %p, refcnt = "
@@ -328,6 +328,7 @@ lobject_dealloc(PyObject* obj)
     if (lobject_close(self) < 0)
         PyErr_Print();
     Py_XDECREF((PyObject*)self->conn);
+    PyMem_Free(self->smode);
 
     Dprintf("lobject_dealloc: deleted lobject object at %p, refcnt = "
             FORMAT_CODE_PY_SSIZE_T, obj, Py_REFCNT(obj));
@@ -339,16 +340,16 @@ static int
 lobject_init(PyObject *obj, PyObject *args, PyObject *kwds)
 {
     Oid oid=InvalidOid, new_oid=InvalidOid;
-    int mode=0;
+    const char *smode = "";
     const char *new_file = NULL;
     PyObject *conn;
 
-    if (!PyArg_ParseTuple(args, "O|iiis",
-         &conn, &oid, &mode, &new_oid, &new_file))
+    if (!PyArg_ParseTuple(args, "O|iziz",
+         &conn, &oid, &smode, &new_oid, &new_file))
         return -1;
 
     return lobject_setup((lobjectObject *)obj,
-        (connectionObject *)conn, oid, mode, new_oid, new_file);
+        (connectionObject *)conn, oid, smode, new_oid, new_file);
 }
 
 static PyObject *
diff --git a/tests/test_lobject.py b/tests/test_lobject.py
index 7f600e3..3e99e86 100755
--- a/tests/test_lobject.py
+++ b/tests/test_lobject.py
@@ -84,7 +84,7 @@ class LargeObjectTests(LargeObjectMixin, unittest.TestCase):
     def test_create(self):
         lo = self.conn.lobject()
         self.assertNotEqual(lo, None)
-        self.assertEqual(lo.mode, "w")
+        self.assertEqual(lo.mode[0], "w")
 
     def test_open_non_existent(self):
         # By creating then removing a large object, we get an Oid that
@@ -98,12 +98,12 @@ class LargeObjectTests(LargeObjectMixin, unittest.TestCase):
         lo2 = self.conn.lobject(lo.oid)
         self.assertNotEqual(lo2, None)
         self.assertEqual(lo2.oid, lo.oid)
-        self.assertEqual(lo2.mode, "r")
+        self.assertEqual(lo2.mode[0], "r")
 
     def test_open_for_write(self):
         lo = self.conn.lobject()
         lo2 = self.conn.lobject(lo.oid, "w")
-        self.assertEqual(lo2.mode, "w")
+        self.assertEqual(lo2.mode[0], "w")
         lo2.write(b("some data"))
 
     def test_open_mode_n(self):