]> arthur.barton.de Git - bup.git/blobdiff - lib/bup/_helpers.c
Drop support for python 2
[bup.git] / lib / bup / _helpers.c
index 5b9ace9b6bac81a32bf77cc3f382cc8bf89d865e..9265d49324a72b08f82132ae427eb105875263b7 100644 (file)
@@ -4,7 +4,6 @@
 #include "../../config/config.h"
 
 // According to Python, its header has to go first:
-//   http://docs.python.org/2/c-api/intro.html#include-files
 //   http://docs.python.org/3/c-api/intro.html#include-files
 #include <Python.h>
 
@@ -66,6 +65,7 @@
 #endif
 
 #include "bupsplit.h"
+#include "bup/intprops.h"
 
 #if defined(FS_IOC_GETFLAGS) && defined(FS_IOC_SETFLAGS)
 #define BUP_HAVE_FILE_ATTRS 1
@@ -102,18 +102,10 @@ typedef struct {
 // rbuf_argf: for read-only byte vectors
 // wbuf_argf: for mutable byte vectors
 
-#if PY_MAJOR_VERSION < 3
-static state_t state;
-#  define get_state(x) (&state)
-#  define cstr_argf "s"
-#  define rbuf_argf "s#"
-#  define wbuf_argf "s*"
-#else
-#  define get_state(x) ((state_t *) PyModule_GetState(x))
-#  define cstr_argf "y"
-#  define rbuf_argf "y#"
-#  define wbuf_argf "y*"
-#endif // PY_MAJOR_VERSION >= 3
+#define get_state(x) ((state_t *) PyModule_GetState(x))
+#define cstr_argf "y"
+#define rbuf_argf "y#"
+#define wbuf_argf "y*"
 
 
 static void *checked_calloc(size_t n, size_t size)
@@ -124,16 +116,10 @@ static void *checked_calloc(size_t n, size_t size)
     return result;
 }
 
-#ifndef BUP_HAVE_BUILTIN_MUL_OVERFLOW
-
-#define checked_malloc checked_calloc
-
-#else // defined BUP_HAVE_BUILTIN_MUL_OVERFLOW
-
 static void *checked_malloc(size_t n, size_t size)
 {
     size_t total;
-    if (__builtin_mul_overflow(n, size, &total))
+    if (!INT_MULTIPLY_OK(n, size, &total))
     {
         PyErr_Format(PyExc_OverflowError,
                      "request to allocate %zu items of size %zu is too large",
@@ -146,8 +132,6 @@ static void *checked_malloc(size_t n, size_t size)
     return result;
 }
 
-#endif // defined BUP_HAVE_BUILTIN_MUL_OVERFLOW
-
 
 #ifndef htonll
 // This function should technically be macro'd out if it's going to be used
@@ -163,69 +147,14 @@ static uint64_t htonll(uint64_t value)
 }
 #endif
 
+#define INTEGRAL_ASSIGNMENT_FITS(dest, src) INT_ADD_OK(src, 0, dest)
 
-// Disabling sign-compare here should be fine since we're explicitly
-// checking for a sign mismatch, i.e. if the signs don't match, then
-// it doesn't matter what the value comparison says.
-// FIXME: ... so should we reverse the order?
-#define INTEGRAL_ASSIGNMENT_FITS(dest, src)                             \
-    ({                                                                  \
-        _Pragma("GCC diagnostic push");                                 \
-        _Pragma("GCC diagnostic ignored \"-Wsign-compare\"");           \
-        _Pragma("clang diagnostic push");                               \
-        _Pragma("clang diagnostic ignored \"-Wshorten-64-to-32\"");     \
-        *(dest) = (src);                                                \
-        int result = *(dest) == (src) && (*(dest) < 1) == ((src) < 1);  \
-        _Pragma("clang diagnostic pop");                                \
-        _Pragma("GCC diagnostic pop");                                  \
-        result;                                                         \
-    })
-
-
-#define INTEGER_TO_PY(x)                                                \
-    ({                                                                  \
-        _Pragma("GCC diagnostic push");                                 \
-        _Pragma("GCC diagnostic ignored \"-Wtype-limits\"");   \
-        _Pragma("clang diagnostic push");                               \
-        _Pragma("clang diagnostic ignored \"-Wtautological-compare\""); \
-        PyObject *result = ((x) >= 0) ? PyLong_FromUnsignedLongLong(x) : PyLong_FromLongLong(x); \
-        _Pragma("clang diagnostic pop");                                \
-        _Pragma("GCC diagnostic pop");                                  \
-        result;                                                         \
-    })
-
-
-#if PY_MAJOR_VERSION < 3
-static int bup_ulong_from_pyint(unsigned long *x, PyObject *py,
-                                const char *name)
-{
-    const long tmp = PyInt_AsLong(py);
-    if (tmp == -1 && PyErr_Occurred())
-    {
-        if (PyErr_ExceptionMatches(PyExc_OverflowError))
-            PyErr_Format(PyExc_OverflowError, "%s too big for unsigned long",
-                         name);
-        return 0;
-    }
-    if (tmp < 0)
-    {
-        PyErr_Format(PyExc_OverflowError,
-                     "negative %s cannot be converted to unsigned long", name);
-        return 0;
-    }
-    *x = tmp;
-    return 1;
-}
-#endif
+#define INTEGER_TO_PY(x) \
+    EXPR_SIGNED(x) ? PyLong_FromLongLong(x) : PyLong_FromUnsignedLongLong(x)
 
 
 static int bup_ulong_from_py(unsigned long *x, PyObject *py, const char *name)
 {
-#if PY_MAJOR_VERSION < 3
-    if (PyInt_Check(py))
-        return bup_ulong_from_pyint(x, py, name);
-#endif
-
     if (!PyLong_Check(py))
     {
         PyErr_Format(PyExc_TypeError, "expected integer %s", name);
@@ -263,19 +192,6 @@ static int bup_uint_from_py(unsigned int *x, PyObject *py, const char *name)
 static int bup_ullong_from_py(unsigned PY_LONG_LONG *x, PyObject *py,
                               const char *name)
 {
-#if PY_MAJOR_VERSION < 3
-    if (PyInt_Check(py))
-    {
-        unsigned long tmp;
-        if (bup_ulong_from_pyint(&tmp, py, name))
-        {
-            *x = tmp;
-            return 1;
-        }
-        return 0;
-    }
-#endif
-
     if (!PyLong_Check(py))
     {
         PyErr_Format(PyExc_TypeError, "integer argument expected for %s", name);
@@ -372,15 +288,11 @@ static int write_all(int fd, const void *buf, const size_t count)
 }
 
 
-static int uadd(unsigned long long *dest,
-                const unsigned long long x,
-                const unsigned long long y)
+static inline int uadd(unsigned long long *dest,
+                       const unsigned long long x,
+                       const unsigned long long y)
 {
-    const unsigned long long result = x + y;
-    if (result < x || result < y)
-        return 0;
-    *dest = result;
-    return 1;
+    return INT_ADD_OK(x, y, dest);
 }
 
 
@@ -607,29 +519,13 @@ static PyObject *blobbits(PyObject *self, PyObject *args)
 
 static PyObject *splitbuf(PyObject *self, PyObject *args)
 {
-    // We stick to buffers in python 2 because they appear to be
-    // substantially smaller than memoryviews, and because
-    // zlib.compress() in python 2 can't accept a memoryview
-    // (cf. hashsplit.py).
     int out = 0, bits = -1;
-    if (PY_MAJOR_VERSION > 2)
-    {
-        Py_buffer buf;
-        if (!PyArg_ParseTuple(args, "y*", &buf))
-            return NULL;
-        assert(buf.len <= INT_MAX);
-        out = bupsplit_find_ofs(buf.buf, buf.len, &bits);
-        PyBuffer_Release(&buf);
-    }
-    else
-    {
-        unsigned char *buf = NULL;
-        Py_ssize_t len = 0;
-        if (!PyArg_ParseTuple(args, "t#", &buf, &len))
-            return NULL;
-        assert(len <= INT_MAX);
-        out = bupsplit_find_ofs(buf, (int) len, &bits);
-    }
+    Py_buffer buf;
+    if (!PyArg_ParseTuple(args, "y*", &buf))
+        return NULL;
+    assert(buf.len <= INT_MAX);
+    out = bupsplit_find_ofs(buf.buf, buf.len, &bits);
+    PyBuffer_Release(&buf);
     if (out) assert(bits >= BUP_BLOBBITS);
     return Py_BuildValue("ii", out, bits);
 }
@@ -658,8 +554,14 @@ static PyObject *bitmatch(PyObject *self, PyObject *args)
        }
     }
     
-    assert(byte <= (INT_MAX >> 3));
-    return Py_BuildValue("i", byte*8 + bit);
+    Py_ssize_t result;
+    if (!INT_MULTIPLY_OK(byte, 8, &result)
+        || !INT_ADD_OK(result, bit, &result))
+    {
+        PyErr_Format(PyExc_OverflowError, "bitmatch bit count too large");
+        return NULL;
+    }
+    return PyLong_FromSsize_t(result);
 }
 
 
@@ -1701,6 +1603,81 @@ static PyObject *bup_mincore(PyObject *self, PyObject *args)
 }
 #endif /* def BUP_MINCORE_BUF_TYPE */
 
+static unsigned int vuint_encode(long long val, char *buf)
+{
+    unsigned int len = 0;
+
+    if (val < 0) {
+        PyErr_SetString(PyExc_Exception, "vuints must not be negative");
+        return 0;
+    }
+
+    do {
+        buf[len] = val & 0x7f;
+
+        val >>= 7;
+        if (val)
+            buf[len] |= 0x80;
+
+        len++;
+    } while (val);
+
+    return len;
+}
+
+static unsigned int vint_encode(long long val, char *buf)
+{
+    unsigned int len = 1;
+    char sign = 0;
+
+    if (val < 0) {
+        sign = 0x40;
+        val = -val;
+    }
+
+    buf[0] = (val & 0x3f) | sign;
+    val >>= 6;
+    if (val)
+        buf[0] |= 0x80;
+
+    while (val) {
+        buf[len] = val & 0x7f;
+        val >>= 7;
+        if (val)
+            buf[len] |= 0x80;
+        len++;
+    }
+
+    return len;
+}
+
+static PyObject *bup_vuint_encode(PyObject *self, PyObject *args)
+{
+    long long val;
+    // size the buffer appropriately - need 8 bits to encode each 7
+    char buf[(sizeof(val) + 1) / 7 * 8];
+
+    if (!PyArg_ParseTuple(args, "L", &val))
+       return NULL;
+
+    unsigned int len = vuint_encode(val, buf);
+    if (!len)
+        return NULL;
+
+    return PyBytes_FromStringAndSize(buf, len);
+}
+
+static PyObject *bup_vint_encode(PyObject *self, PyObject *args)
+{
+    long long val;
+    // size the buffer appropriately - need 8 bits to encode each 7
+    char buf[(sizeof(val) + 1) / 7 * 8];
+
+    if (!PyArg_ParseTuple(args, "L", &val))
+       return NULL;
+
+    return PyBytes_FromStringAndSize(buf, vint_encode(val, buf));
+}
 
 static PyObject *tuple_from_cstrs(char **cstrs)
 {
@@ -1852,6 +1829,7 @@ static PyObject *bup_gethostname(PyObject *mod, PyObject *ignore)
 
     if (gethostname(buf, sizeof(buf) - 1))
         return PyErr_SetFromErrno(PyExc_IOError);
+    buf[sizeof(buf) - 1] = 0;
     return PyBytes_FromString(buf);
 }
 
@@ -1865,10 +1843,18 @@ static char *cstr_from_bytes(PyObject *bytes)
     int rc = PyBytes_AsStringAndSize(bytes, &buf, &length);
     if (rc == -1)
         return NULL;
-    char *result = checked_malloc(length, sizeof(char));
+    size_t c_len;
+    if (!INT_ADD_OK(length, 1, &c_len)) {
+        PyErr_Format(PyExc_OverflowError,
+                     "Cannot convert ssize_t sized bytes object (%zd) to C string",
+                     length);
+        return NULL;
+    }
+    char *result = checked_malloc(c_len, sizeof(char));
     if (!result)
         return NULL;
     memcpy(result, buf, length);
+    result[length] = 0;
     return result;
 }
 
@@ -1938,15 +1924,11 @@ bup_set_completer_word_break_characters(PyObject *self, PyObject *args)
 static PyObject *
 bup_get_completer_word_break_characters(PyObject *self, PyObject *args)
 {
-    if (!PyArg_ParseTuple(args, ""))
-       return NULL;
     return PyBytes_FromString(rl_completer_word_break_characters);
 }
 
 static PyObject *bup_get_line_buffer(PyObject *self, PyObject *args)
 {
-    if (!PyArg_ParseTuple(args, ""))
-       return NULL;
     return PyBytes_FromString(rl_line_buffer);
 }
 
@@ -2197,6 +2179,95 @@ static PyObject *bup_apply_acl(PyObject *self, PyObject *args)
 }
 #endif
 
+static PyObject *bup_limited_vint_pack(PyObject *self, PyObject *args)
+{
+    const char *fmt;
+    PyObject *packargs, *result;
+    Py_ssize_t sz, i, bufsz;
+    char *buf, *pos, *end;
+
+    if (!PyArg_ParseTuple(args, "sO", &fmt, &packargs))
+        return NULL;
+
+    if (!PyTuple_Check(packargs))
+        return PyErr_Format(PyExc_Exception, "pack() arg must be tuple");
+
+    sz = PyTuple_GET_SIZE(packargs);
+    if (sz != (Py_ssize_t)strlen(fmt))
+        return PyErr_Format(PyExc_Exception,
+                            "number of arguments (%ld) does not match format string (%ld)",
+                            (unsigned long)sz, (unsigned long)strlen(fmt));
+
+    if (sz > INT_MAX / 20)
+        return PyErr_Format(PyExc_Exception, "format is far too long");
+
+    // estimate no more than 20 bytes for each on average, the maximum
+    // vint/vuint we can encode is anyway 10 bytes, so this gives us
+    // some headroom for a few strings before we need to realloc ...
+    bufsz = sz * 20;
+    buf = malloc(bufsz);
+    if (!buf)
+        return PyErr_NoMemory();
+
+    pos = buf;
+    end = buf + bufsz;
+    for (i = 0; i < sz; i++) {
+        PyObject *item = PyTuple_GET_ITEM(packargs, i);
+        const char *bytes;
+
+        switch (fmt[i]) {
+        case 'V': {
+            long long val = PyLong_AsLongLong(item);
+            if (val == -1 && PyErr_Occurred())
+                return PyErr_Format(PyExc_OverflowError,
+                                    "pack arg %d invalid", (int)i);
+            if (end - pos < 10)
+                goto overflow;
+           pos += vuint_encode(val, pos);
+            break;
+        }
+        case 'v': {
+            long long val = PyLong_AsLongLong(item);
+            if (val == -1 && PyErr_Occurred())
+                return PyErr_Format(PyExc_OverflowError,
+                                    "pack arg %d invalid", (int)i);
+            if (end - pos < 10)
+                goto overflow;
+            pos += vint_encode(val, pos);
+            break;
+        }
+        case 's': {
+            bytes = PyBytes_AsString(item);
+            if (!bytes)
+                goto error;
+            if (end - pos < 10)
+                goto overflow;
+            Py_ssize_t val = PyBytes_GET_SIZE(item);
+            pos += vuint_encode(val, pos);
+            if (end - pos < val)
+                goto overflow;
+            memcpy(pos, bytes, val);
+            pos += val;
+            break;
+        }
+        default:
+            PyErr_Format(PyExc_Exception, "unknown xpack format string item %c",
+                         fmt[i]);
+            goto error;
+        }
+    }
+
+    result = PyBytes_FromStringAndSize(buf, pos - buf);
+    free(buf);
+    return result;
+
+ overflow:
+    PyErr_SetString(PyExc_OverflowError, "buffer (potentially) overflowed");
+ error:
+    free(buf);
+    return NULL;
+}
+
 static PyMethodDef helper_methods[] = {
     { "write_sparsely", bup_write_sparsely, METH_VARARGS,
       "Write buf excepting zeros at the end. Return trailing zero count." },
@@ -2316,6 +2387,10 @@ static PyMethodDef helper_methods[] = {
       "apply_acl(name, acl, def=None)\n\n"
       "Given a file/dirname (bytes) and the ACLs to restore, do that." },
 #endif /* HAVE_ACLS */
+    { "vuint_encode", bup_vuint_encode, METH_VARARGS, "encode an int to vuint" },
+    { "vint_encode", bup_vint_encode, METH_VARARGS, "encode an int to vint" },
+    { "limited_vint_pack", bup_limited_vint_pack, METH_VARARGS,
+      "Try to pack vint/vuint/str, throwing OverflowError when unable." },
     { NULL, NULL, 0, NULL },  // sentinel
 };
 
@@ -2361,6 +2436,9 @@ static int setup_module(PyObject *m)
     // Just be sure (relevant when passing timestamps back to Python above).
     assert(sizeof(PY_LONG_LONG) <= sizeof(long long));
     assert(sizeof(unsigned PY_LONG_LONG) <= sizeof(unsigned long long));
+    // At least for INTEGER_TO_PY
+    assert(sizeof(intmax_t) <= sizeof(long long));
+    assert(sizeof(uintmax_t) <= sizeof(unsigned long long));
 
     test_integral_assignment_fits();
 
@@ -2417,25 +2495,6 @@ static int setup_module(PyObject *m)
 }
 
 
-#if PY_MAJOR_VERSION < 3
-
-PyMODINIT_FUNC init_helpers(void)
-{
-    PyObject *m = Py_InitModule("_helpers", helper_methods);
-    if (m == NULL) {
-        PyErr_SetString(PyExc_RuntimeError, "bup._helpers init failed");
-        return;
-    }
-    if (!setup_module(m))
-    {
-        PyErr_SetString(PyExc_RuntimeError, "bup._helpers set up failed");
-        Py_DECREF(m);
-        return;
-    }
-}
-
-# else // PY_MAJOR_VERSION >= 3
-
 static struct PyModuleDef helpers_def = {
     PyModuleDef_HEAD_INIT,
     "_helpers",
@@ -2460,5 +2519,3 @@ PyMODINIT_FUNC PyInit__helpers(void)
     }
     return module;
 }
-
-#endif // PY_MAJOR_VERSION >= 3