add LZ4_decompress_safe(), access lz4_decompress_safe()

setup.py

@@ -1,11 +1,17 @@
 #!/usr/bin/env python
 
 
-from setuptools import setup, find_packages, Extension
+from distutils.core import setup, Extension
+import sys
 
 VERSION = (0, 7, 0)
 VERSION_STR = ".".join([str(x) for x in VERSION])
 
+kwarg=dict()
+if sys.version_info >= (2, 7):
+    kwarg['setup_requires']=["nose>=1.0"]
+    kwarg['test_suite'] = "nose.collector"
+
 setup(
     name='lz4',
     version=VERSION_STR,
@@ -14,7 +20,7 @@
     author='Steeve Morin',
     author_email='[email protected]',
     url='https://github.com/steeve/python-lz4',
-    packages=find_packages('src'),
+    packages=[],
     package_dir={'': 'src'},
     ext_modules=[
         Extension('lz4', [
@@ -23,16 +29,14 @@
             'src/python-lz4.c'
         ], extra_compile_args=[
             "-std=c99",
-            "-O3",
+#            "-O3",
             "-Wall",
             "-W",
             "-Wundef",
             "-DVERSION=\"%s\"" % VERSION_STR,
             "-DLZ4_VERSION=\"r119\"",
         ])
     ],
-    setup_requires=["nose>=1.0"],
-    test_suite = "nose.collector",
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'License :: OSI Approved :: BSD License',
@@ -42,5 +46,6 @@
         'Programming Language :: Python :: 2.6',
         'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3.3',
-    ],
+    ], 
+    **kwarg
 )

src/python-lz4.c

@@ -125,6 +125,53 @@ static PyObject *py_lz4_uncompress(PyObject *self, PyObject *args) {
     return result;
 }
 
+/*
+ * access to the original lz4_decompress_safe() function
+ * expect 3 arguments 
+ *  - a compressed string in raw format (without the size header)
+ *  - inputSize, the number of bytes to use from the compressed string, 
+ *    if zero then use all the string
+ *  - maxOutputSize, the size of the output buffer, if too small then
+ *    raise a ValueError exception, if too big then resized to match
+ *    the uncompressed size.
+ */
+static PyObject *py_lz4_decompress_safe(PyObject *self, PyObject *args) {
+    PyObject *result;
+    const char *source;
+    int source_size;
+    int inputSize;
+    int maxOutputSize;
+
+    if (!PyArg_ParseTuple(args, "s#ii", &source, &source_size, &inputSize, &maxOutputSize)) {
+        return NULL;
+    }
+
+    if (inputSize > source_size) {
+        PyErr_SetString(PyExc_ValueError, "inputSize bigger than source length");
+        return NULL;
+    }
+
+    if (inputSize == 0) {
+        inputSize = source_size;
+    }
+
+    result = PyBytes_FromStringAndSize(NULL, maxOutputSize);
+    if (result != NULL) {
+        char *dest = PyBytes_AS_STRING(result);
+        int osize = LZ4_decompress_safe(source, dest, inputSize, maxOutputSize);
+        if (osize < 0) {
+            PyErr_Format(PyExc_ValueError, "corrupt input at byte %d", -osize);
+            Py_CLEAR(result);
+        } 
+        if (osize < maxOutputSize) {
+            if (_PyBytes_Resize(&result, osize) < 0) {
+                return NULL;
+            }
+        }
+    }
+    return result;
+}
+
 static PyMethodDef Lz4Methods[] = {
     {"LZ4_compress",  py_lz4_compress, METH_VARARGS, COMPRESS_DOCSTRING},
     {"LZ4_uncompress",  py_lz4_uncompress, METH_VARARGS, UNCOMPRESS_DOCSTRING},
@@ -134,6 +181,7 @@ static PyMethodDef Lz4Methods[] = {
     {"decompress",  py_lz4_uncompress, METH_VARARGS, UNCOMPRESS_DOCSTRING},
     {"dumps",  py_lz4_compress, METH_VARARGS, COMPRESS_DOCSTRING},
     {"loads",  py_lz4_uncompress, METH_VARARGS, UNCOMPRESS_DOCSTRING},
+    {"LZ4_decompress_safe",  py_lz4_decompress_safe, METH_VARARGS, LZ4_DECOMPRESS_SAFE_DOCSTRING},
     {NULL, NULL, 0, NULL}
 };
 

src/python-lz4.h

@@ -33,12 +33,14 @@
 
 static PyObject *py_lz4_compress(PyObject *self, PyObject *args);
 static PyObject *py_lz4_uncompress(PyObject *self, PyObject *args);
+static PyObject *py_lz4_decompress_safe(PyObject *self, PyObject *args);
 
 PyMODINIT_FUNC initlz4(void);
 
 #define COMPRESS_DOCSTRING      "Compress string, returning the compressed data.\nRaises an exception if any error occurs."
 #define COMPRESSHC_DOCSTRING    COMPRESS_DOCSTRING "\n\nCompared to compress, this gives a better compression ratio, but is much slower."
 #define UNCOMPRESS_DOCSTRING    "Decompress string, returning the uncompressed data.\nRaises an exception if any error occurs."
+#define LZ4_DECOMPRESS_SAFE_DOCSTRING   "Decompress raw string, returning the uncompressed data.\nRaises an exception if any error occurs."
 
 #if defined(_WIN32) && defined(_MSC_VER)
 # define inline __inline