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Diffstat (limited to 'Objects/stringlib/split.h')
| -rw-r--r-- | Objects/stringlib/split.h | 788 |
1 files changed, 788 insertions, 0 deletions
diff --git a/Objects/stringlib/split.h b/Objects/stringlib/split.h new file mode 100644 index 0000000..00b29b3 --- /dev/null +++ b/Objects/stringlib/split.h @@ -0,0 +1,788 @@ +/* stringlib: split implementation */ + +#ifndef STRINGLIB_SPLIT_H +#define STRINGLIB_SPLIT_H + +#ifndef STRINGLIB_FASTSEARCH_H +#error must include "stringlib/fastsearch.h" before including this module +#endif + +/* Overallocate the initial list to reduce the number of reallocs for small + split sizes. Eg, "A A A A A A A A A A".split() (10 elements) has three + resizes, to sizes 4, 8, then 16. Most observed string splits are for human + text (roughly 11 words per line) and field delimited data (usually 1-10 + fields). For large strings the split algorithms are bandwidth limited + so increasing the preallocation likely will not improve things.*/ + +#define MAX_PREALLOC 12 + +/* 5 splits gives 6 elements */ +#define PREALLOC_SIZE(maxsplit) \ + (maxsplit >= MAX_PREALLOC ? MAX_PREALLOC : maxsplit+1) + +#define SPLIT_APPEND(data, left, right) \ + sub = STRINGLIB_NEW((data) + (left), \ + (right) - (left)); \ + if (sub == NULL) \ + goto onError; \ + if (PyList_Append(list, sub)) { \ + Py_DECREF(sub); \ + goto onError; \ + } \ + else \ + Py_DECREF(sub); + +#define SPLIT_ADD(data, left, right) { \ + sub = STRINGLIB_NEW((data) + (left), \ + (right) - (left)); \ + if (sub == NULL) \ + goto onError; \ + if (count < MAX_PREALLOC) { \ + PyList_SET_ITEM(list, count, sub); \ + } else { \ + if (PyList_Append(list, sub)) { \ + Py_DECREF(sub); \ + goto onError; \ + } \ + else \ + Py_DECREF(sub); \ + } \ + count++; } + + +/* Always force the list to the expected size. */ +#define FIX_PREALLOC_SIZE(list) Py_SIZE(list) = count + +Py_LOCAL_INLINE(PyObject *) +stringlib_split_whitespace(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, count=0; + PyObject *list = PyList_New(PREALLOC_SIZE(maxcount)); + PyObject *sub; + + if (list == NULL) + return NULL; + + i = j = 0; + while (maxcount-- > 0) { + while (i < str_len && STRINGLIB_ISSPACE(str[i])) + i++; + if (i == str_len) break; + j = i; i++; + while (i < str_len && !STRINGLIB_ISSPACE(str[i])) + i++; +#ifndef STRINGLIB_MUTABLE + if (j == 0 && i == str_len && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No whitespace in str_obj, so just use it as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + break; + } +#endif + SPLIT_ADD(str, j, i); + } + + if (i < str_len) { + /* Only occurs when maxcount was reached */ + /* Skip any remaining whitespace and copy to end of string */ + while (i < str_len && STRINGLIB_ISSPACE(str[i])) + i++; + if (i != str_len) + SPLIT_ADD(str, i, str_len); + } + FIX_PREALLOC_SIZE(list); + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_split_char(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + const STRINGLIB_CHAR ch, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, count=0; + PyObject *list = PyList_New(PREALLOC_SIZE(maxcount)); + PyObject *sub; + + if (list == NULL) + return NULL; + + i = j = 0; + while ((j < str_len) && (maxcount-- > 0)) { + for(; j < str_len; j++) { + /* I found that using memchr makes no difference */ + if (str[j] == ch) { + SPLIT_ADD(str, i, j); + i = j = j + 1; + break; + } + } + } +#ifndef STRINGLIB_MUTABLE + if (count == 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* ch not in str_obj, so just use str_obj as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + } else +#endif + if (i <= str_len) { + SPLIT_ADD(str, i, str_len); + } + FIX_PREALLOC_SIZE(list); + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_split(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + const STRINGLIB_CHAR* sep, Py_ssize_t sep_len, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, pos, count=0; + PyObject *list, *sub; + + if (sep_len == 0) { + PyErr_SetString(PyExc_ValueError, "empty separator"); + return NULL; + } + else if (sep_len == 1) + return stringlib_split_char(str_obj, str, str_len, sep[0], maxcount); + + list = PyList_New(PREALLOC_SIZE(maxcount)); + if (list == NULL) + return NULL; + + i = j = 0; + while (maxcount-- > 0) { + pos = fastsearch(str+i, str_len-i, sep, sep_len, -1, FAST_SEARCH); + if (pos < 0) + break; + j = i + pos; + SPLIT_ADD(str, i, j); + i = j + sep_len; + } +#ifndef STRINGLIB_MUTABLE + if (count == 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No match in str_obj, so just use it as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + } else +#endif + { + SPLIT_ADD(str, i, str_len); + } + FIX_PREALLOC_SIZE(list); + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_rsplit_whitespace(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, count=0; + PyObject *list = PyList_New(PREALLOC_SIZE(maxcount)); + PyObject *sub; + + if (list == NULL) + return NULL; + + i = j = str_len - 1; + while (maxcount-- > 0) { + while (i >= 0 && STRINGLIB_ISSPACE(str[i])) + i--; + if (i < 0) break; + j = i; i--; + while (i >= 0 && !STRINGLIB_ISSPACE(str[i])) + i--; +#ifndef STRINGLIB_MUTABLE + if (j == str_len - 1 && i < 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No whitespace in str_obj, so just use it as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + break; + } +#endif + SPLIT_ADD(str, i + 1, j + 1); + } + + if (i >= 0) { + /* Only occurs when maxcount was reached */ + /* Skip any remaining whitespace and copy to beginning of string */ + while (i >= 0 && STRINGLIB_ISSPACE(str[i])) + i--; + if (i >= 0) + SPLIT_ADD(str, 0, i + 1); + } + FIX_PREALLOC_SIZE(list); + if (PyList_Reverse(list) < 0) + goto onError; + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_rsplit_char(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + const STRINGLIB_CHAR ch, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, count=0; + PyObject *list = PyList_New(PREALLOC_SIZE(maxcount)); + PyObject *sub; + + if (list == NULL) + return NULL; + + i = j = str_len - 1; + while ((i >= 0) && (maxcount-- > 0)) { + for(; i >= 0; i--) { + if (str[i] == ch) { + SPLIT_ADD(str, i + 1, j + 1); + j = i = i - 1; + break; + } + } + } +#ifndef STRINGLIB_MUTABLE + if (count == 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* ch not in str_obj, so just use str_obj as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + } else +#endif + if (j >= -1) { + SPLIT_ADD(str, 0, j + 1); + } + FIX_PREALLOC_SIZE(list); + if (PyList_Reverse(list) < 0) + goto onError; + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_rsplit(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + const STRINGLIB_CHAR* sep, Py_ssize_t sep_len, + Py_ssize_t maxcount) +{ + Py_ssize_t j, pos, count=0; + PyObject *list, *sub; + + if (sep_len == 0) { + PyErr_SetString(PyExc_ValueError, "empty separator"); + return NULL; + } + else if (sep_len == 1) + return stringlib_rsplit_char(str_obj, str, str_len, sep[0], maxcount); + + list = PyList_New(PREALLOC_SIZE(maxcount)); + if (list == NULL) + return NULL; + + j = str_len; + while (maxcount-- > 0) { + pos = fastsearch(str, j, sep, sep_len, -1, FAST_RSEARCH); + if (pos < 0) + break; + SPLIT_ADD(str, pos + sep_len, j); + j = pos; + } +#ifndef STRINGLIB_MUTABLE + if (count == 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No match in str_obj, so just use it as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + } else +#endif + { + SPLIT_ADD(str, 0, j); + } + FIX_PREALLOC_SIZE(list); + if (PyList_Reverse(list) < 0) + goto onError; + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_splitlines(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + int keepends) +{ + /* This does not use the preallocated list because splitlines is + usually run with hundreds of newlines. The overhead of + switching between PyList_SET_ITEM and append causes about a + 2-3% slowdown for that common case. A smarter implementation + could move the if check out, so the SET_ITEMs are done first + and the appends only done when the prealloc buffer is full. + That's too much work for little gain.*/ + + register Py_ssize_t i; + register Py_ssize_t j; + PyObject *list = PyList_New(0); + PyObject *sub; + + if (list == NULL) + return NULL; + + for (i = j = 0; i < str_len; ) { + Py_ssize_t eol; + + /* Find a line and append it */ + while (i < str_len && !STRINGLIB_ISLINEBREAK(str[i])) + i++; + + /* Skip the line break reading CRLF as one line break */ + eol = i; + if (i < str_len) { + if (str[i] == '\r' && i + 1 < str_len && str[i+1] == '\n') + i += 2; + else + i++; + if (keepends) + eol = i; + } +#ifndef STRINGLIB_MUTABLE + if (j == 0 && eol == str_len && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No linebreak in str_obj, so just use it as list[0] */ + if (PyList_Append(list, str_obj)) + goto onError; + break; + } +#endif + SPLIT_APPEND(str, j, eol); + j = i; + } + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +#endif +/* stringlib: split implementation */ + +#ifndef STRINGLIB_SPLIT_H +#define STRINGLIB_SPLIT_H + +#ifndef STRINGLIB_FASTSEARCH_H +#error must include "stringlib/fastsearch.h" before including this module +#endif + +/* Overallocate the initial list to reduce the number of reallocs for small + split sizes. Eg, "A A A A A A A A A A".split() (10 elements) has three + resizes, to sizes 4, 8, then 16. Most observed string splits are for human + text (roughly 11 words per line) and field delimited data (usually 1-10 + fields). For large strings the split algorithms are bandwidth limited + so increasing the preallocation likely will not improve things.*/ + +#define MAX_PREALLOC 12 + +/* 5 splits gives 6 elements */ +#define PREALLOC_SIZE(maxsplit) \ + (maxsplit >= MAX_PREALLOC ? MAX_PREALLOC : maxsplit+1) + +#define SPLIT_APPEND(data, left, right) \ + sub = STRINGLIB_NEW((data) + (left), \ + (right) - (left)); \ + if (sub == NULL) \ + goto onError; \ + if (PyList_Append(list, sub)) { \ + Py_DECREF(sub); \ + goto onError; \ + } \ + else \ + Py_DECREF(sub); + +#define SPLIT_ADD(data, left, right) { \ + sub = STRINGLIB_NEW((data) + (left), \ + (right) - (left)); \ + if (sub == NULL) \ + goto onError; \ + if (count < MAX_PREALLOC) { \ + PyList_SET_ITEM(list, count, sub); \ + } else { \ + if (PyList_Append(list, sub)) { \ + Py_DECREF(sub); \ + goto onError; \ + } \ + else \ + Py_DECREF(sub); \ + } \ + count++; } + + +/* Always force the list to the expected size. */ +#define FIX_PREALLOC_SIZE(list) Py_SIZE(list) = count + +Py_LOCAL_INLINE(PyObject *) +stringlib_split_whitespace(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, count=0; + PyObject *list = PyList_New(PREALLOC_SIZE(maxcount)); + PyObject *sub; + + if (list == NULL) + return NULL; + + i = j = 0; + while (maxcount-- > 0) { + while (i < str_len && STRINGLIB_ISSPACE(str[i])) + i++; + if (i == str_len) break; + j = i; i++; + while (i < str_len && !STRINGLIB_ISSPACE(str[i])) + i++; +#ifndef STRINGLIB_MUTABLE + if (j == 0 && i == str_len && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No whitespace in str_obj, so just use it as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + break; + } +#endif + SPLIT_ADD(str, j, i); + } + + if (i < str_len) { + /* Only occurs when maxcount was reached */ + /* Skip any remaining whitespace and copy to end of string */ + while (i < str_len && STRINGLIB_ISSPACE(str[i])) + i++; + if (i != str_len) + SPLIT_ADD(str, i, str_len); + } + FIX_PREALLOC_SIZE(list); + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_split_char(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + const STRINGLIB_CHAR ch, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, count=0; + PyObject *list = PyList_New(PREALLOC_SIZE(maxcount)); + PyObject *sub; + + if (list == NULL) + return NULL; + + i = j = 0; + while ((j < str_len) && (maxcount-- > 0)) { + for(; j < str_len; j++) { + /* I found that using memchr makes no difference */ + if (str[j] == ch) { + SPLIT_ADD(str, i, j); + i = j = j + 1; + break; + } + } + } +#ifndef STRINGLIB_MUTABLE + if (count == 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* ch not in str_obj, so just use str_obj as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + } else +#endif + if (i <= str_len) { + SPLIT_ADD(str, i, str_len); + } + FIX_PREALLOC_SIZE(list); + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_split(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + const STRINGLIB_CHAR* sep, Py_ssize_t sep_len, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, pos, count=0; + PyObject *list, *sub; + + if (sep_len == 0) { + PyErr_SetString(PyExc_ValueError, "empty separator"); + return NULL; + } + else if (sep_len == 1) + return stringlib_split_char(str_obj, str, str_len, sep[0], maxcount); + + list = PyList_New(PREALLOC_SIZE(maxcount)); + if (list == NULL) + return NULL; + + i = j = 0; + while (maxcount-- > 0) { + pos = fastsearch(str+i, str_len-i, sep, sep_len, -1, FAST_SEARCH); + if (pos < 0) + break; + j = i + pos; + SPLIT_ADD(str, i, j); + i = j + sep_len; + } +#ifndef STRINGLIB_MUTABLE + if (count == 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No match in str_obj, so just use it as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + } else +#endif + { + SPLIT_ADD(str, i, str_len); + } + FIX_PREALLOC_SIZE(list); + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_rsplit_whitespace(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, count=0; + PyObject *list = PyList_New(PREALLOC_SIZE(maxcount)); + PyObject *sub; + + if (list == NULL) + return NULL; + + i = j = str_len - 1; + while (maxcount-- > 0) { + while (i >= 0 && STRINGLIB_ISSPACE(str[i])) + i--; + if (i < 0) break; + j = i; i--; + while (i >= 0 && !STRINGLIB_ISSPACE(str[i])) + i--; +#ifndef STRINGLIB_MUTABLE + if (j == str_len - 1 && i < 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No whitespace in str_obj, so just use it as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + break; + } +#endif + SPLIT_ADD(str, i + 1, j + 1); + } + + if (i >= 0) { + /* Only occurs when maxcount was reached */ + /* Skip any remaining whitespace and copy to beginning of string */ + while (i >= 0 && STRINGLIB_ISSPACE(str[i])) + i--; + if (i >= 0) + SPLIT_ADD(str, 0, i + 1); + } + FIX_PREALLOC_SIZE(list); + if (PyList_Reverse(list) < 0) + goto onError; + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_rsplit_char(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + const STRINGLIB_CHAR ch, + Py_ssize_t maxcount) +{ + Py_ssize_t i, j, count=0; + PyObject *list = PyList_New(PREALLOC_SIZE(maxcount)); + PyObject *sub; + + if (list == NULL) + return NULL; + + i = j = str_len - 1; + while ((i >= 0) && (maxcount-- > 0)) { + for(; i >= 0; i--) { + if (str[i] == ch) { + SPLIT_ADD(str, i + 1, j + 1); + j = i = i - 1; + break; + } + } + } +#ifndef STRINGLIB_MUTABLE + if (count == 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* ch not in str_obj, so just use str_obj as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + } else +#endif + if (j >= -1) { + SPLIT_ADD(str, 0, j + 1); + } + FIX_PREALLOC_SIZE(list); + if (PyList_Reverse(list) < 0) + goto onError; + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_rsplit(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + const STRINGLIB_CHAR* sep, Py_ssize_t sep_len, + Py_ssize_t maxcount) +{ + Py_ssize_t j, pos, count=0; + PyObject *list, *sub; + + if (sep_len == 0) { + PyErr_SetString(PyExc_ValueError, "empty separator"); + return NULL; + } + else if (sep_len == 1) + return stringlib_rsplit_char(str_obj, str, str_len, sep[0], maxcount); + + list = PyList_New(PREALLOC_SIZE(maxcount)); + if (list == NULL) + return NULL; + + j = str_len; + while (maxcount-- > 0) { + pos = fastsearch(str, j, sep, sep_len, -1, FAST_RSEARCH); + if (pos < 0) + break; + SPLIT_ADD(str, pos + sep_len, j); + j = pos; + } +#ifndef STRINGLIB_MUTABLE + if (count == 0 && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No match in str_obj, so just use it as list[0] */ + Py_INCREF(str_obj); + PyList_SET_ITEM(list, 0, (PyObject *)str_obj); + count++; + } else +#endif + { + SPLIT_ADD(str, 0, j); + } + FIX_PREALLOC_SIZE(list); + if (PyList_Reverse(list) < 0) + goto onError; + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +Py_LOCAL_INLINE(PyObject *) +stringlib_splitlines(PyObject* str_obj, + const STRINGLIB_CHAR* str, Py_ssize_t str_len, + int keepends) +{ + /* This does not use the preallocated list because splitlines is + usually run with hundreds of newlines. The overhead of + switching between PyList_SET_ITEM and append causes about a + 2-3% slowdown for that common case. A smarter implementation + could move the if check out, so the SET_ITEMs are done first + and the appends only done when the prealloc buffer is full. + That's too much work for little gain.*/ + + register Py_ssize_t i; + register Py_ssize_t j; + PyObject *list = PyList_New(0); + PyObject *sub; + + if (list == NULL) + return NULL; + + for (i = j = 0; i < str_len; ) { + Py_ssize_t eol; + + /* Find a line and append it */ + while (i < str_len && !STRINGLIB_ISLINEBREAK(str[i])) + i++; + + /* Skip the line break reading CRLF as one line break */ + eol = i; + if (i < str_len) { + if (str[i] == '\r' && i + 1 < str_len && str[i+1] == '\n') + i += 2; + else + i++; + if (keepends) + eol = i; + } +#ifndef STRINGLIB_MUTABLE + if (j == 0 && eol == str_len && STRINGLIB_CHECK_EXACT(str_obj)) { + /* No linebreak in str_obj, so just use it as list[0] */ + if (PyList_Append(list, str_obj)) + goto onError; + break; + } +#endif + SPLIT_APPEND(str, j, eol); + j = i; + } + return list; + + onError: + Py_DECREF(list); + return NULL; +} + +#endif |