[Python-checkins] cpython: Split PyUnicode_DecodeCharmap() into subfunction for readability

Thu Apr 18 01:56:36 CEST 2013

http://hg.python.org/cpython/rev/3e02d70cd07b
changeset: 83437:3e02d70cd07b
user: Victor Stinner <victor.stinner at gmail.com>
date: Thu Apr 18 01:44:27 2013 +0200
summary:
 Split PyUnicode_DecodeCharmap() into subfunction for readability
files:
 Objects/unicodeobject.c | 417 +++++++++++++++------------
 1 files changed, 226 insertions(+), 191 deletions(-)

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -7265,19 +7265,234 @@
 
 /* --- Character Mapping Codec -------------------------------------------- */
 
+static int
+charmap_decode_string(const char *s,
+ Py_ssize_t size,
+ PyObject *mapping,
+ const char *errors,
+ _PyUnicodeWriter *writer)
+{
+ const char *starts = s;
+ const char *e;
+ Py_ssize_t startinpos, endinpos;
+ PyObject *errorHandler = NULL, *exc = NULL;
+ Py_ssize_t maplen;
+ enum PyUnicode_Kind mapkind;
+ void *mapdata;
+ Py_UCS4 x;
+ unsigned char ch;
+
+ if (PyUnicode_READY(mapping) == -1)
+ return -1;
+
+ maplen = PyUnicode_GET_LENGTH(mapping);
+ mapdata = PyUnicode_DATA(mapping);
+ mapkind = PyUnicode_KIND(mapping);
+
+ e = s + size;
+
+ if (mapkind == PyUnicode_1BYTE_KIND && maplen >= 256) {
+ /* fast-path for cp037, cp500 and iso8859_1 encodings. iso8859_1
+ * is disabled in encoding aliases, latin1 is preferred because
+ * its implementation is faster. */
+ Py_UCS1 *mapdata_ucs1 = (Py_UCS1 *)mapdata;
+ Py_UCS1 *outdata = (Py_UCS1 *)writer->data;
+ Py_UCS4 maxchar = writer->maxchar;
+
+ assert (writer->kind == PyUnicode_1BYTE_KIND);
+ while (s < e) {
+ ch = *s;
+ x = mapdata_ucs1[ch];
+ if (x > maxchar) {
+ if (_PyUnicodeWriter_Prepare(writer, 1, 0xff) == -1)
+ goto onError;
+ maxchar = writer->maxchar;
+ outdata = (Py_UCS1 *)writer->data;
+ }
+ outdata[writer->pos] = x;
+ writer->pos++;
+ ++s;
+ }
+ return 0;
+ }
+
+ while (s < e) {
+ if (mapkind == PyUnicode_2BYTE_KIND && maplen >= 256) {
+ enum PyUnicode_Kind outkind = writer->kind;
+ Py_UCS2 *mapdata_ucs2 = (Py_UCS2 *)mapdata;
+ if (outkind == PyUnicode_1BYTE_KIND) {
+ Py_UCS1 *outdata = (Py_UCS1 *)writer->data;
+ Py_UCS4 maxchar = writer->maxchar;
+ while (s < e) {
+ ch = *s;
+ x = mapdata_ucs2[ch];
+ if (x > maxchar)
+ goto Error;
+ outdata[writer->pos] = x;
+ writer->pos++;
+ ++s;
+ }
+ break;
+ }
+ else if (outkind == PyUnicode_2BYTE_KIND) {
+ Py_UCS2 *outdata = (Py_UCS2 *)writer->data;
+ while (s < e) {
+ ch = *s;
+ x = mapdata_ucs2[ch];
+ if (x == 0xFFFE)
+ goto Error;
+ outdata[writer->pos] = x;
+ writer->pos++;
+ ++s;
+ }
+ break;
+ }
+ }
+ ch = *s;
+
+ if (ch < maplen)
+ x = PyUnicode_READ(mapkind, mapdata, ch);
+ else
+ x = 0xfffe; /* invalid value */
+Error:
+ if (x == 0xfffe)
+ {
+ /* undefined mapping */
+ startinpos = s-starts;
+ endinpos = startinpos+1;
+ if (unicode_decode_call_errorhandler_writer(
+ errors, &errorHandler,
+ "charmap", "character maps to <undefined>",
+ &starts, &e, &startinpos, &endinpos, &exc, &s,
+ writer)) {
+ goto onError;
+ }
+ continue;
+ }
+
+ if (_PyUnicodeWriter_WriteCharInline(writer, x) < 0)
+ goto onError;
+ ++s;
+ }
+ Py_XDECREF(errorHandler);
+ Py_XDECREF(exc);
+ return 0;
+
+onError:
+ Py_XDECREF(errorHandler);
+ Py_XDECREF(exc);
+ return -1;
+}
+
+static int
+charmap_decode_mapping(const char *s,
+ Py_ssize_t size,
+ PyObject *mapping,
+ const char *errors,
+ _PyUnicodeWriter *writer)
+{
+ const char *starts = s;
+ const char *e;
+ Py_ssize_t startinpos, endinpos;
+ PyObject *errorHandler = NULL, *exc = NULL;
+ unsigned char ch;
+ PyObject *key, *item;
+
+ e = s + size;
+
+ while (s < e) {
+ ch = *s;
+
+ /* Get mapping (char ordinal -> integer, Unicode char or None) */
+ key = PyLong_FromLong((long)ch);
+ if (key == NULL)
+ goto onError;
+
+ item = PyObject_GetItem(mapping, key);
+ Py_DECREF(key);
+ if (item == NULL) {
+ if (PyErr_ExceptionMatches(PyExc_LookupError)) {
+ /* No mapping found means: mapping is undefined. */
+ PyErr_Clear();
+ goto Undefined;
+ } else
+ goto onError;
+ }
+
+ /* Apply mapping */
+ if (item == Py_None)
+ goto Undefined;
+ if (PyLong_Check(item)) {
+ long value = PyLong_AS_LONG(item);
+ if (value == 0xFFFE)
+ goto Undefined;
+ if (value < 0 || value > MAX_UNICODE) {
+ PyErr_Format(PyExc_TypeError,
+ "character mapping must be in range(0x%lx)",
+ (unsigned long)MAX_UNICODE + 1);
+ goto onError;
+ }
+
+ if (_PyUnicodeWriter_WriteCharInline(writer, value) < 0)
+ goto onError;
+ }
+ else if (PyUnicode_Check(item)) {
+ if (PyUnicode_READY(item) == -1)
+ goto onError;
+ if (PyUnicode_GET_LENGTH(item) == 1) {
+ Py_UCS4 value = PyUnicode_READ_CHAR(item, 0);
+ if (value == 0xFFFE)
+ goto Undefined;
+ if (_PyUnicodeWriter_WriteCharInline(writer, value) < 0)
+ goto onError;
+ }
+ else {
+ writer->overallocate = 1;
+ if (_PyUnicodeWriter_WriteStr(writer, item) == -1)
+ goto onError;
+ }
+ }
+ else {
+ /* wrong return value */
+ PyErr_SetString(PyExc_TypeError,
+ "character mapping must return integer, None or str");
+ goto onError;
+ }
+ Py_CLEAR(item);
+ ++s;
+ continue;
+
+Undefined:
+ /* undefined mapping */
+ Py_CLEAR(item);
+ startinpos = s-starts;
+ endinpos = startinpos+1;
+ if (unicode_decode_call_errorhandler_writer(
+ errors, &errorHandler,
+ "charmap", "character maps to <undefined>",
+ &starts, &e, &startinpos, &endinpos, &exc, &s,
+ writer)) {
+ goto onError;
+ }
+ }
+ Py_XDECREF(errorHandler);
+ Py_XDECREF(exc);
+ return 0;
+
+onError:
+ Py_XDECREF(item);
+ Py_XDECREF(errorHandler);
+ Py_XDECREF(exc);
+ return -1;
+}
+
 PyObject *
 PyUnicode_DecodeCharmap(const char *s,
 Py_ssize_t size,
 PyObject *mapping,
 const char *errors)
 {
- const char *starts = s;
- Py_ssize_t startinpos;
- Py_ssize_t endinpos;
- const char *e;
 _PyUnicodeWriter writer;
- PyObject *errorHandler = NULL;
- PyObject *exc = NULL;
 
 /* Default to Latin-1 */
 if (mapping == NULL)
@@ -7290,197 +7505,17 @@
 if (_PyUnicodeWriter_Prepare(&writer, writer.min_length, 127) == -1)
 goto onError;
 
- e = s + size;
 if (PyUnicode_CheckExact(mapping)) {
- Py_ssize_t maplen;
- enum PyUnicode_Kind mapkind;
- void *mapdata;
- Py_UCS4 x;
- unsigned char ch;
-
- if (PyUnicode_READY(mapping) == -1)
- return NULL;
-
- maplen = PyUnicode_GET_LENGTH(mapping);
- mapdata = PyUnicode_DATA(mapping);
- mapkind = PyUnicode_KIND(mapping);
-
- if (mapkind == PyUnicode_1BYTE_KIND && maplen >= 256) {
- /* fast-path for cp037, cp500 and iso8859_1 encodings. iso8859_1
- * is disabled in encoding aliases, latin1 is preferred because
- * its implementation is faster. */
- Py_UCS1 *mapdata_ucs1 = (Py_UCS1 *)mapdata;
- Py_UCS1 *outdata = (Py_UCS1 *)writer.data;
- Py_UCS4 maxchar = writer.maxchar;
-
- assert (writer.kind == PyUnicode_1BYTE_KIND);
- while (s < e) {
- ch = *s;
- x = mapdata_ucs1[ch];
- if (x > maxchar) {
- if (_PyUnicodeWriter_Prepare(&writer, 1, 0xff) == -1)
- goto onError;
- maxchar = writer.maxchar;
- outdata = (Py_UCS1 *)writer.data;
- }
- outdata[writer.pos] = x;
- writer.pos++;
- ++s;
- }
- }
-
- while (s < e) {
- if (mapkind == PyUnicode_2BYTE_KIND && maplen >= 256) {
- enum PyUnicode_Kind outkind = writer.kind;
- Py_UCS2 *mapdata_ucs2 = (Py_UCS2 *)mapdata;
- if (outkind == PyUnicode_1BYTE_KIND) {
- Py_UCS1 *outdata = (Py_UCS1 *)writer.data;
- Py_UCS4 maxchar = writer.maxchar;
- while (s < e) {
- ch = *s;
- x = mapdata_ucs2[ch];
- if (x > maxchar)
- goto Error;
- outdata[writer.pos] = x;
- writer.pos++;
- ++s;
- }
- break;
- }
- else if (outkind == PyUnicode_2BYTE_KIND) {
- Py_UCS2 *outdata = (Py_UCS2 *)writer.data;
- while (s < e) {
- ch = *s;
- x = mapdata_ucs2[ch];
- if (x == 0xFFFE)
- goto Error;
- outdata[writer.pos] = x;
- writer.pos++;
- ++s;
- }
- break;
- }
- }
- ch = *s;
-
- if (ch < maplen)
- x = PyUnicode_READ(mapkind, mapdata, ch);
- else
- x = 0xfffe; /* invalid value */
-Error:
- if (x == 0xfffe)
- {
- /* undefined mapping */
- startinpos = s-starts;
- endinpos = startinpos+1;
- if (unicode_decode_call_errorhandler_writer(
- errors, &errorHandler,
- "charmap", "character maps to <undefined>",
- &starts, &e, &startinpos, &endinpos, &exc, &s,
- &writer)) {
- goto onError;
- }
- continue;
- }
-
- if (_PyUnicodeWriter_WriteCharInline(&writer, x) < 0)
- goto onError;
- ++s;
- }
+ if (charmap_decode_string(s, size, mapping, errors, &writer) < 0)
+ goto onError;
 }
 else {
- while (s < e) {
- unsigned char ch = *s;
- PyObject *w, *x;
-
- /* Get mapping (char ordinal -> integer, Unicode char or None) */
- w = PyLong_FromLong((long)ch);
- if (w == NULL)
- goto onError;
- x = PyObject_GetItem(mapping, w);
- Py_DECREF(w);
- if (x == NULL) {
- if (PyErr_ExceptionMatches(PyExc_LookupError)) {
- /* No mapping found means: mapping is undefined. */
- PyErr_Clear();
- goto Undefined;
- } else
- goto onError;
- }
-
- /* Apply mapping */
- if (x == Py_None)
- goto Undefined;
- if (PyLong_Check(x)) {
- long value = PyLong_AS_LONG(x);
- if (value == 0xFFFE)
- goto Undefined;
- if (value < 0 || value > MAX_UNICODE) {
- PyErr_Format(PyExc_TypeError,
- "character mapping must be in range(0x%lx)",
- (unsigned long)MAX_UNICODE + 1);
- Py_DECREF(x);
- goto onError;
- }
-
- if (_PyUnicodeWriter_WriteCharInline(&writer, value) < 0) {
- Py_DECREF(x);
- goto onError;
- }
- }
- else if (PyUnicode_Check(x)) {
- if (PyUnicode_READY(x) == -1) {
- Py_DECREF(x);
- goto onError;
- }
- if (PyUnicode_GET_LENGTH(x) == 1) {
- Py_UCS4 value = PyUnicode_READ_CHAR(x, 0);
- if (value == 0xFFFE)
- goto Undefined;
- if (_PyUnicodeWriter_WriteCharInline(&writer, value) < 0) {
- Py_DECREF(x);
- goto onError;
- }
- }
- else {
- writer.overallocate = 1;
- if (_PyUnicodeWriter_WriteStr(&writer, x) == -1) {
- Py_DECREF(x);
- goto onError;
- }
- }
- }
- else {
- /* wrong return value */
- PyErr_SetString(PyExc_TypeError,
- "character mapping must return integer, None or str");
- Py_DECREF(x);
- goto onError;
- }
- Py_DECREF(x);
- ++s;
- continue;
-Undefined:
- /* undefined mapping */
- Py_XDECREF(x);
- startinpos = s-starts;
- endinpos = startinpos+1;
- if (unicode_decode_call_errorhandler_writer(
- errors, &errorHandler,
- "charmap", "character maps to <undefined>",
- &starts, &e, &startinpos, &endinpos, &exc, &s,
- &writer)) {
- goto onError;
- }
- }
- }
- Py_XDECREF(errorHandler);
- Py_XDECREF(exc);
+ if (charmap_decode_mapping(s, size, mapping, errors, &writer) < 0)
+ goto onError;
+ }
 return _PyUnicodeWriter_Finish(&writer);
 
 onError:
- Py_XDECREF(errorHandler);
- Py_XDECREF(exc);
 _PyUnicodeWriter_Dealloc(&writer);
 return NULL;
 }
-- 
Repository URL: http://hg.python.org/cpython
