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naschemenascheme
committed
The logreader object did not always refill the input buffer correctly
and got confused by certain log files. Remove logreader_refill and the associated logic and replace with fgetc.
1 parent d7abe2a commit 8b6b491

1 file changed

Lines changed: 56 additions & 105 deletions

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‎Modules/_hotshot.c‎

Lines changed: 56 additions & 105 deletions
Original file line numberDiff line numberDiff line change
@@ -83,11 +83,8 @@ typedef struct {
8383
PyObject_HEAD
8484
PyObject *info;
8585
FILE *logfp;
86-
int filled;
87-
int index;
8886
int linetimings;
8987
int frametimings;
90-
unsigned char buffer[BUFFERSIZE];
9188
} LogReaderObject;
9289

9390
static PyObject * ProfilerError = NULL;
@@ -272,25 +269,21 @@ logreader_tp_iter(LogReaderObject *self)
272269
static int
273270
unpack_packed_int(LogReaderObject *self, int *pvalue, int discard)
274271
{
272+
int c;
275273
int accum = 0;
276274
int bits = 0;
277-
int index = self->index;
278275
int cont;
279276

280277
do {
281-
if (index >= self->filled)
282-
return ERR_EOF;
283278
/* read byte */
284-
accum |= ((self->buffer[index] & 0x7F) >> discard) << bits;
279+
if ((c = fgetc(self->logfp)) == EOF)
280+
return ERR_EOF;
281+
accum |= ((c & 0x7F) >> discard) << bits;
285282
bits += (7 - discard);
286-
cont = self->buffer[index] & 0x80;
287-
/* move to next */
283+
cont = c & 0x80;
288284
discard = 0;
289-
index++;
290285
} while (cont);
291286

292-
/* save state */
293-
self->index = index;
294287
*pvalue = accum;
295288

296289
return 0;
@@ -302,43 +295,37 @@ unpack_packed_int(LogReaderObject *self, int *pvalue, int discard)
302295
static int
303296
unpack_string(LogReaderObject *self, PyObject **pvalue)
304297
{
298+
int i;
305299
int len;
306-
int oldindex = self->index;
307-
int err = unpack_packed_int(self, &len, 0);
308-
309-
if (!err) {
310-
/* need at least len bytes in buffer */
311-
if (len > (self->filled - self->index)) {
312-
self->index = oldindex;
313-
err = ERR_EOF;
314-
}
315-
else {
316-
*pvalue = PyString_FromStringAndSize((char *)self->buffer + self->index,
317-
len);
318-
if (*pvalue == NULL) {
319-
self->index = oldindex;
320-
err = ERR_EXCEPTION;
321-
}
322-
else
323-
self->index += len;
300+
int err;
301+
char *buf;
302+
303+
if ((err = unpack_packed_int(self, &len, 0)))
304+
return err;
305+
306+
buf = malloc(len);
307+
for (i=0; i < len; i++) {
308+
if ((buf[i] = fgetc(self->logfp)) == EOF) {
309+
free(buf);
310+
return ERR_EOF;
324311
}
325312
}
326-
return err;
313+
*pvalue = PyString_FromStringAndSize(buf, len);
314+
free(buf);
315+
if (*pvalue == NULL) {
316+
return ERR_EXCEPTION;
317+
}
318+
return 0;
327319
}
328320

329321

330322
static int
331-
unpack_add_info(LogReaderObject *self, int skip_opcode)
323+
unpack_add_info(LogReaderObject *self)
332324
{
333325
PyObject *key;
334326
PyObject *value = NULL;
335327
int err;
336328

337-
if (skip_opcode) {
338-
if (self->buffer[self->index] != WHAT_ADD_INFO)
339-
return ERR_BAD_RECTYPE;
340-
self->index++;
341-
}
342329
err = unpack_string(self, &key);
343330
if (!err) {
344331
err = unpack_string(self, &value);
@@ -368,25 +355,6 @@ unpack_add_info(LogReaderObject *self, int skip_opcode)
368355
}
369356

370357

371-
static void
372-
logreader_refill(LogReaderObject *self)
373-
{
374-
int needed;
375-
size_t res;
376-
377-
if (self->index) {
378-
memmove(self->buffer, &self->buffer[self->index],
379-
self->filled - self->index);
380-
self->filled = self->filled - self->index;
381-
self->index = 0;
382-
}
383-
needed = BUFFERSIZE - self->filled;
384-
if (needed > 0) {
385-
res = fread(&self->buffer[self->filled], 1, needed, self->logfp);
386-
self->filled += res;
387-
}
388-
}
389-
390358
static void
391359
eof_error(void)
392360
{
@@ -397,7 +365,8 @@ eof_error(void)
397365
static PyObject *
398366
logreader_tp_iternext(LogReaderObject *self)
399367
{
400-
int what, oldindex;
368+
int c;
369+
int what;
401370
int err = ERR_NONE;
402371
int lineno = -1;
403372
int fileno = -1;
@@ -413,22 +382,18 @@ logreader_tp_iternext(LogReaderObject *self)
413382
"cannot iterate over closed LogReader object");
414383
return NULL;
415384
}
416-
restart:
417-
if ((self->filled - self->index) < MAXEVENTSIZE)
418-
logreader_refill(self);
419385

420-
/* end of input */
421-
if (self->filled == 0)
386+
restart:
387+
/* decode the record type */
388+
if ((c = fgetc(self->logfp)) == EOF)
422389
return NULL;
423390

424-
oldindex = self->index;
391+
what = c & WHAT_OTHER;
392+
if (what == WHAT_OTHER)
393+
what = c; /* need all the bits for type */
394+
else
395+
ungetc(c, self->logfp); /* type byte includes packed int */
425396

426-
/* decode the record type */
427-
what = self->buffer[self->index] & WHAT_OTHER;
428-
if (what == WHAT_OTHER) {
429-
what = self->buffer[self->index];
430-
self->index++;
431-
}
432397
switch (what) {
433398
case WHAT_ENTER:
434399
err = unpack_packed_int(self, &fileno, 2);
@@ -447,7 +412,7 @@ logreader_tp_iternext(LogReaderObject *self)
447412
err = unpack_packed_int(self, &tdelta, 0);
448413
break;
449414
case WHAT_ADD_INFO:
450-
err = unpack_add_info(self, 0);
415+
err = unpack_add_info(self);
451416
break;
452417
case WHAT_DEFINE_FILE:
453418
err = unpack_packed_int(self, &fileno, 0);
@@ -468,40 +433,29 @@ logreader_tp_iternext(LogReaderObject *self)
468433
}
469434
break;
470435
case WHAT_LINE_TIMES:
471-
if (self->index >= self->filled)
436+
if ((c = fgetc(self->logfp)) == EOF)
472437
err = ERR_EOF;
473438
else {
474-
self->linetimings = self->buffer[self->index] ? 1 : 0;
475-
self->index++;
476-
goto restart;
477-
}
439+
self->linetimings = c ? 1 : 0;
440+
goto restart;
441+
}
478442
break;
479443
case WHAT_FRAME_TIMES:
480-
if (self->index >= self->filled)
444+
if ((c = fgetc(self->logfp)) == EOF)
481445
err = ERR_EOF;
482446
else {
483-
self->frametimings = self->buffer[self->index] ? 1 : 0;
484-
self->index++;
485-
goto restart;
486-
}
447+
self->frametimings = c ? 1 : 0;
448+
goto restart;
449+
}
487450
break;
488451
default:
489452
err = ERR_BAD_RECTYPE;
490453
}
491-
if (err == ERR_EOF && oldindex != 0) {
492-
/* It looks like we ran out of data before we had it all; this
493-
* could easily happen with large packed integers or string
494-
* data. Try forcing the buffer to be re-filled before failing.
495-
*/
496-
err = ERR_NONE;
497-
logreader_refill(self);
498-
}
499454
if (err == ERR_BAD_RECTYPE) {
500455
PyErr_SetString(PyExc_ValueError,
501456
"unknown record type in log file");
502457
}
503458
else if (err == ERR_EOF) {
504-
/* Could not avoid end-of-buffer error. */
505459
eof_error();
506460
}
507461
else if (!err) {
@@ -1389,12 +1343,12 @@ hotshot_logreader(PyObject *unused, PyObject *args)
13891343
{
13901344
LogReaderObject *self = NULL;
13911345
char *filename;
1346+
int c;
1347+
int err = 0;
13921348

13931349
if (PyArg_ParseTuple(args, "s:logreader", &filename)) {
13941350
self = PyObject_New(LogReaderObject, &LogReaderType);
13951351
if (self != NULL) {
1396-
self->filled = 0;
1397-
self->index = 0;
13981352
self->frametimings = 1;
13991353
self->linetimings = 0;
14001354
self->info = NULL;
@@ -1410,14 +1364,17 @@ hotshot_logreader(PyObject *unused, PyObject *args)
14101364
Py_DECREF(self);
14111365
goto finally;
14121366
}
1413-
/* Aggressively attempt to load all preliminary ADD_INFO
1414-
* records from the log so the info records are available
1415-
* from a fresh logreader object.
1416-
*/
1417-
logreader_refill(self);
1418-
while (self->filled > self->index
1419-
&& self->buffer[self->index] == WHAT_ADD_INFO) {
1420-
int err = unpack_add_info(self, 1);
1367+
/* read initial info */
1368+
for (;;) {
1369+
if ((c = fgetc(self->logfp)) == EOF) {
1370+
eof_error();
1371+
break;
1372+
}
1373+
if (c != WHAT_ADD_INFO) {
1374+
ungetc(c, self->logfp);
1375+
break;
1376+
}
1377+
err = unpack_add_info(self);
14211378
if (err) {
14221379
if (err == ERR_EOF)
14231380
eof_error();
@@ -1426,12 +1383,6 @@ hotshot_logreader(PyObject *unused, PyObject *args)
14261383
"unexpected error");
14271384
break;
14281385
}
1429-
/* Refill agressively so we can avoid EOF during
1430-
* initialization unless there's a real EOF condition
1431-
* (the tp_iternext handler loops attempts to refill
1432-
* and try again).
1433-
*/
1434-
logreader_refill(self);
14351386
}
14361387
}
14371388
}

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