ref: d39d1a5303541539f61488317b220c1eb724d7d3
dir: /sys/src/cmd/hg/mercurial/parsers.c/
/*
parsers.c - efficient content parsing
Copyright 2008 Matt Mackall <mpm@selenic.com> and others
This software may be used and distributed according to the terms of
the GNU General Public License, incorporated herein by reference.
*/
#include <Python.h>
#include <ctype.h>
#include <string.h>
static int hexdigit(char c)
{
if (c >= '0' && c <= '9')
return c - '0';
if (c >= 'a' && c <= 'f')
return c - 'a' + 10;
if (c >= 'A' && c <= 'F')
return c - 'A' + 10;
PyErr_SetString(PyExc_ValueError, "input contains non-hex character");
return 0;
}
/*
* Turn a hex-encoded string into binary.
*/
static PyObject *unhexlify(const char *str, int len)
{
PyObject *ret;
const char *c;
char *d;
ret = PyString_FromStringAndSize(NULL, len / 2);
if (!ret)
return NULL;
d = PyString_AS_STRING(ret);
for (c = str; c < str + len;) {
int hi = hexdigit(*c++);
int lo = hexdigit(*c++);
*d++ = (hi << 4) | lo;
}
return ret;
}
/*
* This code assumes that a manifest is stitched together with newline
* ('\n') characters.
*/
static PyObject *parse_manifest(PyObject *self, PyObject *args)
{
PyObject *mfdict, *fdict;
char *str, *cur, *start, *zero;
int len;
if (!PyArg_ParseTuple(args, "O!O!s#:parse_manifest",
&PyDict_Type, &mfdict,
&PyDict_Type, &fdict,
&str, &len))
goto quit;
for (start = cur = str, zero = NULL; cur < str + len; cur++) {
PyObject *file = NULL, *node = NULL;
PyObject *flags = NULL;
int nlen;
if (!*cur) {
zero = cur;
continue;
}
else if (*cur != '\n')
continue;
if (!zero) {
PyErr_SetString(PyExc_ValueError,
"manifest entry has no separator");
goto quit;
}
file = PyString_FromStringAndSize(start, zero - start);
if (!file)
goto bail;
nlen = cur - zero - 1;
node = unhexlify(zero + 1, nlen > 40 ? 40 : nlen);
if (!node)
goto bail;
if (nlen > 40) {
PyObject *flags;
flags = PyString_FromStringAndSize(zero + 41,
nlen - 40);
if (!flags)
goto bail;
if (PyDict_SetItem(fdict, file, flags) == -1)
goto bail;
}
if (PyDict_SetItem(mfdict, file, node) == -1)
goto bail;
start = cur + 1;
zero = NULL;
Py_XDECREF(flags);
Py_XDECREF(node);
Py_XDECREF(file);
continue;
bail:
Py_XDECREF(flags);
Py_XDECREF(node);
Py_XDECREF(file);
goto quit;
}
if (len > 0 && *(cur - 1) != '\n') {
PyErr_SetString(PyExc_ValueError,
"manifest contains trailing garbage");
goto quit;
}
Py_INCREF(Py_None);
return Py_None;
quit:
return NULL;
}
#ifdef _WIN32
# ifdef _MSC_VER
/* msvc 6.0 has problems */
# define inline __inline
typedef unsigned long uint32_t;
typedef unsigned __int64 uint64_t;
# else
# include <stdint.h>
# endif
static uint32_t ntohl(uint32_t x)
{
return ((x & 0x000000ffUL) << 24) |
((x & 0x0000ff00UL) << 8) |
((x & 0x00ff0000UL) >> 8) |
((x & 0xff000000UL) >> 24);
}
#else
/* not windows */
# include <sys/types.h>
# if defined __BEOS__ && !defined __HAIKU__
# include <ByteOrder.h>
# else
# include <arpa/inet.h>
# endif
# include <inttypes.h>
#endif
static PyObject *parse_dirstate(PyObject *self, PyObject *args)
{
PyObject *dmap, *cmap, *parents = NULL, *ret = NULL;
PyObject *fname = NULL, *cname = NULL, *entry = NULL;
char *str, *cur, *end, *cpos;
int state, mode, size, mtime;
unsigned int flen;
int len;
char decode[16]; /* for alignment */
if (!PyArg_ParseTuple(args, "O!O!s#:parse_dirstate",
&PyDict_Type, &dmap,
&PyDict_Type, &cmap,
&str, &len))
goto quit;
/* read parents */
if (len < 40)
goto quit;
parents = Py_BuildValue("s#s#", str, 20, str + 20, 20);
if (!parents)
goto quit;
/* read filenames */
cur = str + 40;
end = str + len;
while (cur < end - 17) {
/* unpack header */
state = *cur;
memcpy(decode, cur + 1, 16);
mode = ntohl(*(uint32_t *)(decode));
size = ntohl(*(uint32_t *)(decode + 4));
mtime = ntohl(*(uint32_t *)(decode + 8));
flen = ntohl(*(uint32_t *)(decode + 12));
cur += 17;
if (flen > end - cur) {
PyErr_SetString(PyExc_ValueError, "overflow in dirstate");
goto quit;
}
entry = Py_BuildValue("ciii", state, mode, size, mtime);
if (!entry)
goto quit;
PyObject_GC_UnTrack(entry); /* don't waste time with this */
cpos = memchr(cur, 0, flen);
if (cpos) {
fname = PyString_FromStringAndSize(cur, cpos - cur);
cname = PyString_FromStringAndSize(cpos + 1,
flen - (cpos - cur) - 1);
if (!fname || !cname ||
PyDict_SetItem(cmap, fname, cname) == -1 ||
PyDict_SetItem(dmap, fname, entry) == -1)
goto quit;
Py_DECREF(cname);
} else {
fname = PyString_FromStringAndSize(cur, flen);
if (!fname ||
PyDict_SetItem(dmap, fname, entry) == -1)
goto quit;
}
cur += flen;
Py_DECREF(fname);
Py_DECREF(entry);
fname = cname = entry = NULL;
}
ret = parents;
Py_INCREF(ret);
quit:
Py_XDECREF(fname);
Py_XDECREF(cname);
Py_XDECREF(entry);
Py_XDECREF(parents);
return ret;
}
const char nullid[20];
const int nullrev = -1;
/* create an index tuple, insert into the nodemap */
static PyObject * _build_idx_entry(PyObject *nodemap, int n, uint64_t offset_flags,
int comp_len, int uncomp_len, int base_rev,
int link_rev, int parent_1, int parent_2,
const char *c_node_id)
{
int err;
PyObject *entry, *node_id, *n_obj;
node_id = PyString_FromStringAndSize(c_node_id, 20);
n_obj = PyInt_FromLong(n);
if (!node_id || !n_obj)
err = -1;
else
err = PyDict_SetItem(nodemap, node_id, n_obj);
Py_XDECREF(n_obj);
if (err)
goto error_dealloc;
entry = Py_BuildValue("LiiiiiiN", offset_flags, comp_len,
uncomp_len, base_rev, link_rev,
parent_1, parent_2, node_id);
if (!entry)
goto error_dealloc;
PyObject_GC_UnTrack(entry); /* don't waste time with this */
return entry;
error_dealloc:
Py_XDECREF(node_id);
return NULL;
}
/* RevlogNG format (all in big endian, data may be inlined):
* 6 bytes: offset
* 2 bytes: flags
* 4 bytes: compressed length
* 4 bytes: uncompressed length
* 4 bytes: base revision
* 4 bytes: link revision
* 4 bytes: parent 1 revision
* 4 bytes: parent 2 revision
* 32 bytes: nodeid (only 20 bytes used)
*/
static int _parse_index_ng (const char *data, int size, int inlined,
PyObject *index, PyObject *nodemap)
{
PyObject *entry;
int n = 0, err;
uint64_t offset_flags;
int comp_len, uncomp_len, base_rev, link_rev, parent_1, parent_2;
const char *c_node_id;
const char *end = data + size;
char decode[64]; /* to enforce alignment with inline data */
while (data < end) {
unsigned int step;
memcpy(decode, data, 64);
offset_flags = ntohl(*((uint32_t *) (decode + 4)));
if (n == 0) /* mask out version number for the first entry */
offset_flags &= 0xFFFF;
else {
uint32_t offset_high = ntohl(*((uint32_t *) decode));
offset_flags |= ((uint64_t) offset_high) << 32;
}
comp_len = ntohl(*((uint32_t *) (decode + 8)));
uncomp_len = ntohl(*((uint32_t *) (decode + 12)));
base_rev = ntohl(*((uint32_t *) (decode + 16)));
link_rev = ntohl(*((uint32_t *) (decode + 20)));
parent_1 = ntohl(*((uint32_t *) (decode + 24)));
parent_2 = ntohl(*((uint32_t *) (decode + 28)));
c_node_id = decode + 32;
entry = _build_idx_entry(nodemap, n, offset_flags,
comp_len, uncomp_len, base_rev,
link_rev, parent_1, parent_2,
c_node_id);
if (!entry)
return 0;
if (inlined) {
err = PyList_Append(index, entry);
Py_DECREF(entry);
if (err)
return 0;
} else
PyList_SET_ITEM(index, n, entry); /* steals reference */
n++;
step = 64 + (inlined ? comp_len : 0);
if (end - data < step)
break;
data += step;
}
if (data != end) {
if (!PyErr_Occurred())
PyErr_SetString(PyExc_ValueError, "corrupt index file");
return 0;
}
/* create the nullid/nullrev entry in the nodemap and the
* magic nullid entry in the index at [-1] */
entry = _build_idx_entry(nodemap,
nullrev, 0, 0, 0, -1, -1, -1, -1, nullid);
if (!entry)
return 0;
if (inlined) {
err = PyList_Append(index, entry);
Py_DECREF(entry);
if (err)
return 0;
} else
PyList_SET_ITEM(index, n, entry); /* steals reference */
return 1;
}
/* This function parses a index file and returns a Python tuple of the
* following format: (index, nodemap, cache)
*
* index: a list of tuples containing the RevlogNG records
* nodemap: a dict mapping node ids to indices in the index list
* cache: if data is inlined, a tuple (index_file_content, 0) else None
*/
static PyObject *parse_index(PyObject *self, PyObject *args)
{
const char *data;
int size, inlined;
PyObject *rval = NULL, *index = NULL, *nodemap = NULL, *cache = NULL;
PyObject *data_obj = NULL, *inlined_obj;
if (!PyArg_ParseTuple(args, "s#O", &data, &size, &inlined_obj))
return NULL;
inlined = inlined_obj && PyObject_IsTrue(inlined_obj);
/* If no data is inlined, we know the size of the index list in
* advance: size divided by size of one one revlog record (64 bytes)
* plus one for the nullid */
index = inlined ? PyList_New(0) : PyList_New(size / 64 + 1);
if (!index)
goto quit;
nodemap = PyDict_New();
if (!nodemap)
goto quit;
/* set up the cache return value */
if (inlined) {
/* Note that the reference to data_obj is only borrowed */
data_obj = PyTuple_GET_ITEM(args, 0);
cache = Py_BuildValue("iO", 0, data_obj);
if (!cache)
goto quit;
} else {
cache = Py_None;
Py_INCREF(Py_None);
}
/* actually populate the index and the nodemap with data */
if (!_parse_index_ng (data, size, inlined, index, nodemap))
goto quit;
rval = Py_BuildValue("NNN", index, nodemap, cache);
if (!rval)
goto quit;
return rval;
quit:
Py_XDECREF(index);
Py_XDECREF(nodemap);
Py_XDECREF(cache);
Py_XDECREF(rval);
return NULL;
}
static char parsers_doc[] = "Efficient content parsing.";
static PyMethodDef methods[] = {
{"parse_manifest", parse_manifest, METH_VARARGS, "parse a manifest\n"},
{"parse_dirstate", parse_dirstate, METH_VARARGS, "parse a dirstate\n"},
{"parse_index", parse_index, METH_VARARGS, "parse a revlog index\n"},
{NULL, NULL}
};
PyMODINIT_FUNC initparsers(void)
{
Py_InitModule3("parsers", methods, parsers_doc);
}