123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612 |
- /*
- * Copyright 2011-present Facebook, Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- #pragma once
- #define FOLLY_STRING_H_
- #include <cstdarg>
- #include <exception>
- #include <string>
- #include <unordered_map>
- #include <unordered_set>
- #include <vector>
- #include <folly/Conv.h>
- #include <folly/ExceptionString.h>
- #include <folly/FBString.h>
- #include <folly/FBVector.h>
- #include <folly/Portability.h>
- #include <folly/Range.h>
- #include <folly/ScopeGuard.h>
- #include <folly/Traits.h>
- // Compatibility function, to make sure toStdString(s) can be called
- // to convert a std::string or fbstring variable s into type std::string
- // with very little overhead if s was already std::string
- namespace folly {
- inline std::string toStdString(const folly::fbstring& s) {
- return std::string(s.data(), s.size());
- }
- inline const std::string& toStdString(const std::string& s) {
- return s;
- }
- // If called with a temporary, the compiler will select this overload instead
- // of the above, so we don't return a (lvalue) reference to a temporary.
- inline std::string&& toStdString(std::string&& s) {
- return std::move(s);
- }
- /**
- * C-Escape a string, making it suitable for representation as a C string
- * literal. Appends the result to the output string.
- *
- * Backslashes all occurrences of backslash and double-quote:
- * " -> \"
- * \ -> \\
- *
- * Replaces all non-printable ASCII characters with backslash-octal
- * representation:
- * <ASCII 254> -> \376
- *
- * Note that we use backslash-octal instead of backslash-hex because the octal
- * representation is guaranteed to consume no more than 3 characters; "\3760"
- * represents two characters, one with value 254, and one with value 48 ('0'),
- * whereas "\xfe0" represents only one character (with value 4064, which leads
- * to implementation-defined behavior).
- */
- template <class String>
- void cEscape(StringPiece str, String& out);
- /**
- * Similar to cEscape above, but returns the escaped string.
- */
- template <class String>
- String cEscape(StringPiece str) {
- String out;
- cEscape(str, out);
- return out;
- }
- /**
- * C-Unescape a string; the opposite of cEscape above. Appends the result
- * to the output string.
- *
- * Recognizes the standard C escape sequences:
- *
- * \' \" \? \\ \a \b \f \n \r \t \v
- * \[0-7]+
- * \x[0-9a-fA-F]+
- *
- * In strict mode (default), throws std::invalid_argument if it encounters
- * an unrecognized escape sequence. In non-strict mode, it leaves
- * the escape sequence unchanged.
- */
- template <class String>
- void cUnescape(StringPiece str, String& out, bool strict = true);
- /**
- * Similar to cUnescape above, but returns the escaped string.
- */
- template <class String>
- String cUnescape(StringPiece str, bool strict = true) {
- String out;
- cUnescape(str, out, strict);
- return out;
- }
- /**
- * URI-escape a string. Appends the result to the output string.
- *
- * Alphanumeric characters and other characters marked as "unreserved" in RFC
- * 3986 ( -_.~ ) are left unchanged. In PATH mode, the forward slash (/) is
- * also left unchanged. In QUERY mode, spaces are replaced by '+'. All other
- * characters are percent-encoded.
- */
- enum class UriEscapeMode : unsigned char {
- // The values are meaningful, see generate_escape_tables.py
- ALL = 0,
- QUERY = 1,
- PATH = 2
- };
- template <class String>
- void uriEscape(
- StringPiece str,
- String& out,
- UriEscapeMode mode = UriEscapeMode::ALL);
- /**
- * Similar to uriEscape above, but returns the escaped string.
- */
- template <class String>
- String uriEscape(StringPiece str, UriEscapeMode mode = UriEscapeMode::ALL) {
- String out;
- uriEscape(str, out, mode);
- return out;
- }
- /**
- * URI-unescape a string. Appends the result to the output string.
- *
- * In QUERY mode, '+' are replaced by space. %XX sequences are decoded if
- * XX is a valid hex sequence, otherwise we throw invalid_argument.
- */
- template <class String>
- void uriUnescape(
- StringPiece str,
- String& out,
- UriEscapeMode mode = UriEscapeMode::ALL);
- /**
- * Similar to uriUnescape above, but returns the unescaped string.
- */
- template <class String>
- String uriUnescape(StringPiece str, UriEscapeMode mode = UriEscapeMode::ALL) {
- String out;
- uriUnescape(str, out, mode);
- return out;
- }
- /**
- * stringPrintf is much like printf but deposits its result into a
- * string. Two signatures are supported: the first simply returns the
- * resulting string, and the second appends the produced characters to
- * the specified string and returns a reference to it.
- */
- std::string stringPrintf(FOLLY_PRINTF_FORMAT const char* format, ...)
- FOLLY_PRINTF_FORMAT_ATTR(1, 2);
- /* Similar to stringPrintf, with different signature. */
- void stringPrintf(std::string* out, FOLLY_PRINTF_FORMAT const char* fmt, ...)
- FOLLY_PRINTF_FORMAT_ATTR(2, 3);
- std::string& stringAppendf(
- std::string* output,
- FOLLY_PRINTF_FORMAT const char* format,
- ...) FOLLY_PRINTF_FORMAT_ATTR(2, 3);
- /**
- * Similar to stringPrintf, but accepts a va_list argument.
- *
- * As with vsnprintf() itself, the value of ap is undefined after the call.
- * These functions do not call va_end() on ap.
- */
- std::string stringVPrintf(const char* format, va_list ap);
- void stringVPrintf(std::string* out, const char* format, va_list ap);
- std::string& stringVAppendf(std::string* out, const char* format, va_list ap);
- /**
- * Backslashify a string, that is, replace non-printable characters
- * with C-style (but NOT C compliant) "\xHH" encoding. If hex_style
- * is false, then shorthand notations like "\0" will be used instead
- * of "\x00" for the most common backslash cases.
- *
- * There are two forms, one returning the input string, and one
- * creating output in the specified output string.
- *
- * This is mainly intended for printing to a terminal, so it is not
- * particularly optimized.
- *
- * Do *not* use this in situations where you expect to be able to feed
- * the string to a C or C++ compiler, as there are nuances with how C
- * parses such strings that lead to failures. This is for display
- * purposed only. If you want a string you can embed for use in C or
- * C++, use cEscape instead. This function is for display purposes
- * only.
- */
- template <class OutputString>
- void backslashify(
- folly::StringPiece input,
- OutputString& output,
- bool hex_style = false);
- template <class OutputString = std::string>
- OutputString backslashify(StringPiece input, bool hex_style = false) {
- OutputString output;
- backslashify(input, output, hex_style);
- return output;
- }
- /**
- * Take a string and "humanify" it -- that is, make it look better.
- * Since "better" is subjective, caveat emptor. The basic approach is
- * to count the number of unprintable characters. If there are none,
- * then the output is the input. If there are relatively few, or if
- * there is a long "enough" prefix of printable characters, use
- * backslashify. If it is mostly binary, then simply hex encode.
- *
- * This is an attempt to make a computer smart, and so likely is wrong
- * most of the time.
- */
- template <class String1, class String2>
- void humanify(const String1& input, String2& output);
- template <class String>
- String humanify(const String& input) {
- String output;
- humanify(input, output);
- return output;
- }
- /**
- * Same functionality as Python's binascii.hexlify. Returns true
- * on successful conversion.
- *
- * If append_output is true, append data to the output rather than
- * replace it.
- */
- template <class InputString, class OutputString>
- bool hexlify(
- const InputString& input,
- OutputString& output,
- bool append = false);
- template <class OutputString = std::string>
- OutputString hexlify(ByteRange input) {
- OutputString output;
- if (!hexlify(input, output)) {
- // hexlify() currently always returns true, so this can't really happen
- throw std::runtime_error("hexlify failed");
- }
- return output;
- }
- template <class OutputString = std::string>
- OutputString hexlify(StringPiece input) {
- return hexlify<OutputString>(ByteRange{input});
- }
- /**
- * Same functionality as Python's binascii.unhexlify. Returns true
- * on successful conversion.
- */
- template <class InputString, class OutputString>
- bool unhexlify(const InputString& input, OutputString& output);
- template <class OutputString = std::string>
- OutputString unhexlify(StringPiece input) {
- OutputString output;
- if (!unhexlify(input, output)) {
- // unhexlify() fails if the input has non-hexidecimal characters,
- // or if it doesn't consist of a whole number of bytes
- throw std::domain_error("unhexlify() called with non-hex input");
- }
- return output;
- }
- /**
- * A pretty-printer for numbers that appends suffixes of units of the
- * given type. It prints 4 sig-figs of value with the most
- * appropriate unit.
- *
- * If `addSpace' is true, we put a space between the units suffix and
- * the value.
- *
- * Current types are:
- * PRETTY_TIME - s, ms, us, ns, etc.
- * PRETTY_TIME_HMS - h, m, s, ms, us, ns, etc.
- * PRETTY_BYTES_METRIC - kB, MB, GB, etc (goes up by 10^3 = 1000 each time)
- * PRETTY_BYTES - kB, MB, GB, etc (goes up by 2^10 = 1024 each time)
- * PRETTY_BYTES_IEC - KiB, MiB, GiB, etc
- * PRETTY_UNITS_METRIC - k, M, G, etc (goes up by 10^3 = 1000 each time)
- * PRETTY_UNITS_BINARY - k, M, G, etc (goes up by 2^10 = 1024 each time)
- * PRETTY_UNITS_BINARY_IEC - Ki, Mi, Gi, etc
- * PRETTY_SI - full SI metric prefixes from yocto to Yotta
- * http://en.wikipedia.org/wiki/Metric_prefix
- *
- * @author Mark Rabkin <mrabkin@fb.com>
- */
- enum PrettyType {
- PRETTY_TIME,
- PRETTY_TIME_HMS,
- PRETTY_BYTES_METRIC,
- PRETTY_BYTES_BINARY,
- PRETTY_BYTES = PRETTY_BYTES_BINARY,
- PRETTY_BYTES_BINARY_IEC,
- PRETTY_BYTES_IEC = PRETTY_BYTES_BINARY_IEC,
- PRETTY_UNITS_METRIC,
- PRETTY_UNITS_BINARY,
- PRETTY_UNITS_BINARY_IEC,
- PRETTY_SI,
- PRETTY_NUM_TYPES,
- };
- std::string prettyPrint(double val, PrettyType, bool addSpace = true);
- /**
- * This utility converts StringPiece in pretty format (look above) to double,
- * with progress information. Alters the StringPiece parameter
- * to get rid of the already-parsed characters.
- * Expects string in form <floating point number> {space}* [<suffix>]
- * If string is not in correct format, utility finds longest valid prefix and
- * if there at least one, returns double value based on that prefix and
- * modifies string to what is left after parsing. Throws and std::range_error
- * exception if there is no correct parse.
- * Examples(for PRETTY_UNITS_METRIC):
- * '10M' => 10 000 000
- * '10 M' => 10 000 000
- * '10' => 10
- * '10 Mx' => 10 000 000, prettyString == "x"
- * 'abc' => throws std::range_error
- */
- double prettyToDouble(
- folly::StringPiece* const prettyString,
- const PrettyType type);
- /**
- * Same as prettyToDouble(folly::StringPiece*, PrettyType), but
- * expects whole string to be correctly parseable. Throws std::range_error
- * otherwise
- */
- double prettyToDouble(folly::StringPiece prettyString, const PrettyType type);
- /**
- * Write a hex dump of size bytes starting at ptr to out.
- *
- * The hex dump is formatted as follows:
- *
- * for the string "abcdefghijklmnopqrstuvwxyz\x02"
- 00000000 61 62 63 64 65 66 67 68 69 6a 6b 6c 6d 6e 6f 70 |abcdefghijklmnop|
- 00000010 71 72 73 74 75 76 77 78 79 7a 02 |qrstuvwxyz. |
- *
- * that is, we write 16 bytes per line, both as hex bytes and as printable
- * characters. Non-printable characters are replaced with '.'
- * Lines are written to out one by one (one StringPiece at a time) without
- * delimiters.
- */
- template <class OutIt>
- void hexDump(const void* ptr, size_t size, OutIt out);
- /**
- * Return the hex dump of size bytes starting at ptr as a string.
- */
- std::string hexDump(const void* ptr, size_t size);
- /**
- * Return a fbstring containing the description of the given errno value.
- * Takes care not to overwrite the actual system errno, so calling
- * errnoStr(errno) is valid.
- */
- fbstring errnoStr(int err);
- /*
- * Split a string into a list of tokens by delimiter.
- *
- * The split interface here supports different output types, selected
- * at compile time: StringPiece, fbstring, or std::string. If you are
- * using a vector to hold the output, it detects the type based on
- * what your vector contains. If the output vector is not empty, split
- * will append to the end of the vector.
- *
- * You can also use splitTo() to write the output to an arbitrary
- * OutputIterator (e.g. std::inserter() on a std::set<>), in which
- * case you have to tell the function the type. (Rationale:
- * OutputIterators don't have a value_type, so we can't detect the
- * type in splitTo without being told.)
- *
- * Examples:
- *
- * std::vector<folly::StringPiece> v;
- * folly::split(":", "asd:bsd", v);
- *
- * std::set<StringPiece> s;
- * folly::splitTo<StringPiece>(":", "asd:bsd:asd:csd",
- * std::inserter(s, s.begin()));
- *
- * Split also takes a flag (ignoreEmpty) that indicates whether adjacent
- * delimiters should be treated as one single separator (ignoring empty tokens)
- * or not (generating empty tokens).
- */
- template <class Delim, class String, class OutputType>
- void split(
- const Delim& delimiter,
- const String& input,
- std::vector<OutputType>& out,
- const bool ignoreEmpty = false);
- template <class Delim, class String, class OutputType>
- void split(
- const Delim& delimiter,
- const String& input,
- folly::fbvector<OutputType>& out,
- const bool ignoreEmpty = false);
- template <
- class OutputValueType,
- class Delim,
- class String,
- class OutputIterator>
- void splitTo(
- const Delim& delimiter,
- const String& input,
- OutputIterator out,
- const bool ignoreEmpty = false);
- /*
- * Split a string into a fixed number of string pieces and/or numeric types
- * by delimiter. Conversions are supported for any type which folly:to<> can
- * target, including all overloads of parseTo(). Returns 'true' if the fields
- * were all successfully populated. Returns 'false' if there were too few
- * fields in the input, or too many fields if exact=true. Casting exceptions
- * will not be caught.
- *
- * Examples:
- *
- * folly::StringPiece name, key, value;
- * if (folly::split('\t', line, name, key, value))
- * ...
- *
- * folly::StringPiece name;
- * double value;
- * int id;
- * if (folly::split('\t', line, name, value, id))
- * ...
- *
- * The 'exact' template parameter specifies how the function behaves when too
- * many fields are present in the input string. When 'exact' is set to its
- * default value of 'true', a call to split will fail if the number of fields in
- * the input string does not exactly match the number of output parameters
- * passed. If 'exact' is overridden to 'false', all remaining fields will be
- * stored, unsplit, in the last field, as shown below:
- *
- * folly::StringPiece x, y.
- * if (folly::split<false>(':', "a:b:c", x, y))
- * assert(x == "a" && y == "b:c");
- *
- * Note that this will likely not work if the last field's target is of numeric
- * type, in which case folly::to<> will throw an exception.
- */
- namespace detail {
- template <typename Void, typename OutputType>
- struct IsConvertible : std::false_type {};
- template <>
- struct IsConvertible<void, decltype(std::ignore)> : std::true_type {};
- template <typename OutputType>
- struct IsConvertible<
- void_t<decltype(parseTo(StringPiece{}, std::declval<OutputType&>()))>,
- OutputType> : std::true_type {};
- } // namespace detail
- template <typename OutputType>
- struct IsConvertible : detail::IsConvertible<void, OutputType> {};
- template <bool exact = true, class Delim, class... OutputTypes>
- typename std::enable_if<
- StrictConjunction<IsConvertible<OutputTypes>...>::value &&
- sizeof...(OutputTypes) >= 1,
- bool>::type
- split(const Delim& delimiter, StringPiece input, OutputTypes&... outputs);
- /*
- * Join list of tokens.
- *
- * Stores a string representation of tokens in the same order with
- * deliminer between each element.
- */
- template <class Delim, class Iterator, class String>
- void join(const Delim& delimiter, Iterator begin, Iterator end, String& output);
- template <class Delim, class Container, class String>
- void join(const Delim& delimiter, const Container& container, String& output) {
- join(delimiter, container.begin(), container.end(), output);
- }
- template <class Delim, class Value, class String>
- void join(
- const Delim& delimiter,
- const std::initializer_list<Value>& values,
- String& output) {
- join(delimiter, values.begin(), values.end(), output);
- }
- template <class Delim, class Container>
- std::string join(const Delim& delimiter, const Container& container) {
- std::string output;
- join(delimiter, container.begin(), container.end(), output);
- return output;
- }
- template <class Delim, class Value>
- std::string join(
- const Delim& delimiter,
- const std::initializer_list<Value>& values) {
- std::string output;
- join(delimiter, values.begin(), values.end(), output);
- return output;
- }
- template <
- class Delim,
- class Iterator,
- typename std::enable_if<std::is_base_of<
- std::forward_iterator_tag,
- typename std::iterator_traits<Iterator>::iterator_category>::value>::
- type* = nullptr>
- std::string join(const Delim& delimiter, Iterator begin, Iterator end) {
- std::string output;
- join(delimiter, begin, end, output);
- return output;
- }
- /**
- * Returns a subpiece with all whitespace removed from the front of @sp.
- * Whitespace means any of [' ', '\n', '\r', '\t'].
- */
- StringPiece ltrimWhitespace(StringPiece sp);
- /**
- * Returns a subpiece with all whitespace removed from the back of @sp.
- * Whitespace means any of [' ', '\n', '\r', '\t'].
- */
- StringPiece rtrimWhitespace(StringPiece sp);
- /**
- * Returns a subpiece with all whitespace removed from the back and front of
- * @sp. Whitespace means any of [' ', '\n', '\r', '\t'].
- */
- inline StringPiece trimWhitespace(StringPiece sp) {
- return ltrimWhitespace(rtrimWhitespace(sp));
- }
- /**
- * Returns a subpiece with all whitespace removed from the front of @sp.
- * Whitespace means any of [' ', '\n', '\r', '\t'].
- * DEPRECATED: @see ltrimWhitespace @see rtrimWhitespace
- */
- inline StringPiece skipWhitespace(StringPiece sp) {
- return ltrimWhitespace(sp);
- }
- /**
- * Strips the leading and the trailing whitespace-only lines. Then looks for
- * the least indented non-whitespace-only line and removes its amount of
- * leading whitespace from every line. Assumes leading whitespace is either all
- * spaces or all tabs.
- *
- * Purpose: including a multiline string literal in source code, indented to
- * the level expected from context.
- */
- std::string stripLeftMargin(std::string s);
- /**
- * Fast, in-place lowercasing of ASCII alphabetic characters in strings.
- * Leaves all other characters unchanged, including those with the 0x80
- * bit set.
- * @param str String to convert
- * @param length Length of str, in bytes
- */
- void toLowerAscii(char* str, size_t length);
- inline void toLowerAscii(MutableStringPiece str) {
- toLowerAscii(str.begin(), str.size());
- }
- inline void toLowerAscii(std::string& str) {
- // str[0] is legal also if the string is empty.
- toLowerAscii(&str[0], str.size());
- }
- } // namespace folly
- #include <folly/String-inl.h>
|