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# Copyright (C) 2008, 2009, 2010 Canonical Ltd
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# Copyright (C) 2008 Canonical Ltd
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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"""Pyrex extensions to btree node parsing."""
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cdef extern from "python-compat.h":
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cdef extern from "stdlib.h":
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ctypedef unsigned size_t
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char *PyString_AsString(object p) except NULL
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object PyString_FromStringAndSize(char *, Py_ssize_t)
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PyObject *PyString_FromStringAndSize_ptr "PyString_FromStringAndSize" (char *, Py_ssize_t)
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int PyString_CheckExact(object s)
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int PyString_CheckExact_ptr "PyString_CheckExact" (PyObject *)
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Py_ssize_t PyString_Size(object p)
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Py_ssize_t PyString_GET_SIZE_ptr "PyString_GET_SIZE" (PyObject *)
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char * PyString_AS_STRING_ptr "PyString_AS_STRING" (PyObject *)
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char * PyString_AS_STRING(object)
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Py_ssize_t PyString_GET_SIZE(object)
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int PyString_AsStringAndSize_ptr(PyObject *, char **buf, Py_ssize_t *len)
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void PyString_InternInPlace(PyObject **)
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int PyTuple_CheckExact(object t)
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object PyTuple_New(Py_ssize_t n_entries)
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void PyTuple_SET_ITEM(object, Py_ssize_t offset, object) # steals the ref
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Py_ssize_t PyTuple_GET_SIZE(object t)
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PyObject *PyTuple_GET_ITEM_ptr_object "PyTuple_GET_ITEM" (object tpl, int index)
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void Py_INCREF(object)
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void Py_DECREF_ptr "Py_DECREF" (PyObject *)
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cdef extern from "string.h":
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void *memcpy(void *dest, void *src, size_t n)
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# void *memrchr(void *s, int c, size_t n)
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int strncmp(char *s1, char *s2, size_t n)
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# It seems we need to import the definitions so that the pyrex compiler has
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# local names to access them.
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from _static_tuple_c cimport StaticTuple, \
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import_static_tuple_c, StaticTuple_New, \
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StaticTuple_Intern, StaticTuple_SET_ITEM, StaticTuple_CheckExact
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# TODO: Find some way to import this from _dirstate_helpers
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cdef void* _my_memrchr(void *s, int c, size_t n): # cannot_raise
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cdef void* _my_memrchr(void *s, int c, size_t n):
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# memrchr seems to be a GNU extension, so we have to implement it ourselves
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# It is not present in any win32 standard library
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return PyString_FromStringAndSize(s, size)
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cdef object safe_interned_string_from_size(char *s, Py_ssize_t size):
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'tried to create a string with an invalid size: %d @0x%x'
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py_str = PyString_FromStringAndSize_ptr(s, size)
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PyString_InternInPlace(&py_str)
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result = <object>py_str
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# Casting a PyObject* to an <object> triggers an INCREF from Pyrex, so we
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# DECREF it to avoid geting immortal strings
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Py_DECREF_ptr(py_str)
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from bzrlib import _static_tuple_c
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# This sets up the StaticTuple C_API functionality
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import_static_tuple_c()
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cdef class BTreeLeafParser:
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"""Parse the leaf nodes of a BTree index.
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cdef char *temp_ptr
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cdef int loop_counter
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key = StaticTuple_New(self.key_length)
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for loop_counter from 0 <= loop_counter < self.key_length:
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while loop_counter < self.key_length:
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loop_counter = loop_counter + 1
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# grab a key segment
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temp_ptr = <char*>memchr(self._start, c'\0', last - self._start)
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if temp_ptr == NULL:
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if loop_counter + 1 == self.key_length:
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if loop_counter == self.key_length:
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# capture to last
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last - self._start)))
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raise AssertionError(failure_string)
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# capture the key string
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if (self.key_length == 1
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and (temp_ptr - self._start) == 45
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and strncmp(self._start, 'sha1:', 5) == 0):
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key_element = safe_string_from_size(self._start,
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temp_ptr - self._start)
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key_element = safe_interned_string_from_size(self._start,
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temp_ptr - self._start)
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# TODO: Consider using PyIntern_FromString, the only caveat is that
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# it assumes a NULL-terminated string, so we have to check if
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# temp_ptr[0] == c'\0' or some other char.
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key_element = safe_string_from_size(self._start,
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temp_ptr - self._start)
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# advance our pointer
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self._start = temp_ptr + 1
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Py_INCREF(key_element)
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StaticTuple_SET_ITEM(key, loop_counter, key_element)
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key = StaticTuple_Intern(key)
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PyList_Append(key_segments, key_element)
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return tuple(key_segments)
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cdef int process_line(self) except -1:
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"""Process a line in the bytes."""
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# And the next string is right after it
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self._cur_str = last + 1
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# The last character is right before the '\n'
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if last == self._start:
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if last < self._start:
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# Unexpected error condition - fail
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raise AssertionError("last < self._start")
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if 0 == self._header_found:
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# The first line in a leaf node is the header "type=leaf\n"
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if strncmp("type=leaf", self._start, last - self._start) == 0:
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raise AssertionError('Node did not start with "type=leaf": %r'
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% (safe_string_from_size(self._start, last - self._start)))
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key = self.extract_key(last)
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# find the value area
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temp_ptr = <char*>_my_memrchr(self._start, c'\0', last - self._start)
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if temp_ptr == NULL:
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raise AssertionError("Failed to find the value area")
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# Because of how conversions were done, we ended up with *lots* of
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# values that are identical. These are all of the 0-length nodes
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# that are referred to by the TREE_ROOT (and likely some other
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# directory nodes.) For example, bzr has 25k references to
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# something like '12607215 328306 0 0', which ends up consuming 1MB
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# of memory, just for those strings.
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str_len = last - temp_ptr - 1
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and strncmp(" 0 0", last - 4, 4) == 0):
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# This drops peak mem for bzr.dev from 87.4MB => 86.2MB
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# For Launchpad 236MB => 232MB
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value = safe_interned_string_from_size(temp_ptr + 1, str_len)
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value = safe_string_from_size(temp_ptr + 1, str_len)
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# capture the value string
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value = safe_string_from_size(temp_ptr + 1, last - temp_ptr - 1)
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# shrink the references end point
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if self.ref_list_length:
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ref_lists = StaticTuple_New(self.ref_list_length)
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while loop_counter < self.ref_list_length:
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# extract a reference list
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loop_counter = loop_counter + 1
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if last < self._start:
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raise AssertionError("last < self._start")
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# find the next reference list end point:
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temp_ptr = <char*>memchr(self._start, c'\t', last - self._start)
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if temp_ptr == NULL:
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# Only valid for the last list
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if loop_counter != self.ref_list_length:
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raise AssertionError(
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"invalid key, loop_counter != self.ref_list_length")
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raise AssertionError("invalid key")
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# scan to the end of the ref list area
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if temp_ptr == NULL:
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# key runs to the end
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temp_ptr = ref_ptr
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PyList_Append(ref_list, self.extract_key(temp_ptr))
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ref_list = StaticTuple_Intern(StaticTuple(*ref_list))
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StaticTuple_SET_ITEM(ref_lists, loop_counter - 1, ref_list)
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PyList_Append(ref_lists, tuple(ref_list))
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# prepare for the next reference list
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self._start = next_start
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node_value = StaticTuple(value, ref_lists)
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ref_lists = tuple(ref_lists)
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node_value = (value, ref_lists)
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if last != self._start:
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# unexpected reference data present
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raise AssertionError("unexpected reference data present")
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node_value = StaticTuple(value, StaticTuple())
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PyList_Append(self.keys, StaticTuple(key, node_value))
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node_value = (value, ())
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PyList_Append(self.keys, (key, node_value))
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cdef int first_ref_list
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cdef int first_reference
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cdef PyObject *ref_bit
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cdef Py_ssize_t ref_bit_len
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if not PyTuple_CheckExact(node) and not StaticTuple_CheckExact(node):
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raise TypeError('We expected a tuple() or StaticTuple() for node not: %s'
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if not PyTuple_CheckExact(node):
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raise TypeError('We expected a tuple() for node not: %s'
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node_len = PyTuple_GET_SIZE(node)
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have_reference_lists = reference_lists
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if have_reference_lists:
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if node_len != 4:
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elif node_len < 3:
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raise ValueError('Without ref_lists, we need at least 3 entries not: %s'
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# TODO: We can probably do better than string.join(), namely
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# when key has only 1 item, we can just grab that string
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# And when there are 2 items, we could do a single malloc + len() + 1
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# also, doing .join() requires a PyObject_GetAttrString call, which
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# we could also avoid.
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# TODO: Note that pyrex 0.9.6 generates fairly crummy code here, using the
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# python object interface, versus 0.9.8+ which uses a helper that
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# checks if this supports the sequence interface.
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# We *could* do more work on our own, and grab the actual items
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# lists. For now, just ask people to use a better compiler. :)
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string_key = '\0'.join(node[1])
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# I don't expect that we can do faster than string.join()
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string_key = '\0'.join(<object>PyTuple_GET_ITEM_ptr_object(node, 1))
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# TODO: instead of using string joins, precompute the final string length,
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# and then malloc a single string and copy everything in.
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if have_reference_lists:
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# Figure out how many bytes it will take to store the references
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ref_lists = <object>PyTuple_GET_ITEM_ptr_object(node, 3)
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next_len = len(ref_lists) # TODO: use a Py function
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# If there are no nodes, we don't need to do any work
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refs_len = refs_len + (next_len - 1)
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for reference in ref_list:
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if (not PyTuple_CheckExact(reference)
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and not StaticTuple_CheckExact(reference)):
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if not PyTuple_CheckExact(reference):
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'We expect references to be tuples not: %s'
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% type(reference))
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next_len = len(reference)
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next_len = PyTuple_GET_SIZE(reference)
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# We will need (len - 1) '\x00' characters to
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# separate the reference key
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refs_len = refs_len + (next_len - 1)
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for ref_bit in reference:
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if not PyString_CheckExact(ref_bit):
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for i from 0 <= i < next_len:
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ref_bit = PyTuple_GET_ITEM_ptr_object(reference, i)
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if not PyString_CheckExact_ptr(ref_bit):
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raise TypeError('We expect reference bits'
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' to be strings not: %s'
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% type(<object>ref_bit))
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refs_len = refs_len + PyString_GET_SIZE(ref_bit)
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refs_len = refs_len + PyString_GET_SIZE_ptr(ref_bit)
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# So we have the (key NULL refs NULL value LF)
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key_len = PyString_Size(string_key)
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if not PyString_CheckExact(val):
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val = PyTuple_GET_ITEM_ptr_object(node, 2)
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if not PyString_CheckExact_ptr(val):
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raise TypeError('Expected a plain str for value not: %s'
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value = PyString_AS_STRING(val)
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value_len = PyString_GET_SIZE(val)
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value = PyString_AS_STRING_ptr(val)
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value_len = PyString_GET_SIZE_ptr(val)
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flat_len = (key_len + 1 + refs_len + 1 + value_len + 1)
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line = PyString_FromStringAndSize(NULL, flat_len)
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# Get a pointer to the new buffer
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first_reference = 0
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next_len = len(reference)
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next_len = PyTuple_GET_SIZE(reference)
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for i from 0 <= i < next_len:
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ref_bit = reference[i]
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ref_bit_len = PyString_GET_SIZE(ref_bit)
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memcpy(out, PyString_AS_STRING(ref_bit), ref_bit_len)
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ref_bit = PyTuple_GET_ITEM_ptr_object(reference, i)
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ref_bit_len = PyString_GET_SIZE_ptr(ref_bit)
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memcpy(out, PyString_AS_STRING_ptr(ref_bit), ref_bit_len)
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out = out + ref_bit_len