From ce42de10fbea616379826e91c7c23c16bffe6e61 Mon Sep 17 00:00:00 2001 From: Abseil Team Date: Wed, 12 May 2021 17:01:06 -0700 Subject: Export of internal Abseil changes -- 9fc37c11b9e46287acef00ee06ed9adcba54dd13 by Greg Falcon : Rename absl::hash_internal::HashState to absl::hash_internal::MixingHashState. Before this change, we had two classes named HashState: absl::HashState, the public API used for type erasure, and absl::hash_internal::HashState, the internal concrete implementation ordinarily used. The internal class used to be named `CityHashState`, but we renamed it to `HashState` it when we changed underlying hash implementation to wyhash. This inadvertent naming conflict made the code much harder to read, and this change intends to undo that. PiperOrigin-RevId: 373481959 -- 4aec55ffddebd085c239352a2e20721091f719a1 by Greg Falcon : Introduce absl::HashOf(), a convenience wrapper around absl::Hash that calculates hashes from the values of its arguments. PiperOrigin-RevId: 373461406 -- 86b5fd8db50bbc8bd0aa9258523527381fe0445d by Abseil Team : Improve speed of BlockingCounter by making its most common path lock free. With the new implementation, the fast path of BlockingCounter::DecrementCount() is only a fetch_sub operation. This is most times much more efficient than the previous implementation (full mutex lock/unlock). As a matter of fact, in most actual usecases in practice, the waiter thread is already waiting on the Wait() call when DecrementCount() is called, which makes Mutex::Unlock() take the slow path as there's a waiter thread that it might need to wake up. PiperOrigin-RevId: 373394164 -- 65c876be5eac0cd32583ff8535ede4109d39cf3f by Martijn Vels : Move the 'sample copied cord' logic into MaybeTrackCord(), This changes move the logic for selecting if a cord should remain being sampled from Cord to CordzInfo::MaybeTrackCord, and updates the documentation for the latter method. PiperOrigin-RevId: 373363168 -- e84410bd0aada293a81dfb82656c952e209e21fb by Martijn Vels : Add check for the first call to cordz_should_profile() for each thread. This prevents the first cord of a newly created thread to be always sampled, which is a 'bad' kind of determinism for sampling. PiperOrigin-RevId: 373229768 -- bf09c589dc099ac8f4af780bf7e609c53c27574c by Samuel Benzaquen : Refactor the Flags structure into an enum. This gives us more control over the representation and allows for easier merging during parsing. PiperOrigin-RevId: 373163038 -- b947b0c51083b7b6508284b5d31819596c91729e by Derek Mauro : Fixes warnings about shadowed variables Fixes #956 PiperOrigin-RevId: 373158133 GitOrigin-RevId: 9fc37c11b9e46287acef00ee06ed9adcba54dd13 Change-Id: I91f35699f9bf439d1a870c6493946a310afe088c --- absl/strings/internal/str_format/parser.h | 40 ++++++++++++++++++------------- 1 file changed, 24 insertions(+), 16 deletions(-) (limited to 'absl/strings/internal/str_format/parser.h') diff --git a/absl/strings/internal/str_format/parser.h b/absl/strings/internal/str_format/parser.h index 6504dd3d..ad8646ed 100644 --- a/absl/strings/internal/str_format/parser.h +++ b/absl/strings/internal/str_format/parser.h @@ -41,10 +41,7 @@ std::string LengthModToString(LengthMod v); // The analyzed properties of a single specified conversion. struct UnboundConversion { - UnboundConversion() - : flags() /* This is required to zero all the fields of flags. */ { - flags.basic = true; - } + UnboundConversion() {} class InputValue { public: @@ -79,7 +76,7 @@ struct UnboundConversion { InputValue width; InputValue precision; - Flags flags; + Flags flags = Flags::kBasic; LengthMod length_mod = LengthMod::none; FormatConversionChar conv = FormatConversionCharInternal::kNone; }; @@ -93,32 +90,43 @@ const char* ConsumeUnboundConversion(const char* p, const char* end, UnboundConversion* conv, int* next_arg); // Helper tag class for the table below. -// It allows fast `char -> ConversionChar/LengthMod` checking and +// It allows fast `char -> ConversionChar/LengthMod/Flags` checking and // conversions. class ConvTag { public: constexpr ConvTag(FormatConversionChar conversion_char) // NOLINT - : tag_(static_cast(conversion_char)) {} - // We invert the length modifiers to make them negative so that we can easily - // test for them. + : tag_(static_cast(conversion_char)) {} constexpr ConvTag(LengthMod length_mod) // NOLINT - : tag_(~static_cast(length_mod)) {} - // Everything else is -128, which is negative to make is_conv() simpler. - constexpr ConvTag() : tag_(-128) {} + : tag_(0x80 | static_cast(length_mod)) {} + constexpr ConvTag(Flags flags) // NOLINT + : tag_(0xc0 | static_cast(flags)) {} + constexpr ConvTag() : tag_(0xFF) {} + + bool is_conv() const { return (tag_ & 0x80) == 0; } + bool is_length() const { return (tag_ & 0xC0) == 0x80; } + bool is_flags() const { return (tag_ & 0xE0) == 0xC0; } - bool is_conv() const { return tag_ >= 0; } - bool is_length() const { return tag_ < 0 && tag_ != -128; } FormatConversionChar as_conv() const { assert(is_conv()); + assert(!is_length()); + assert(!is_flags()); return static_cast(tag_); } LengthMod as_length() const { + assert(!is_conv()); assert(is_length()); - return static_cast(~tag_); + assert(!is_flags()); + return static_cast(tag_ & 0x3F); + } + Flags as_flags() const { + assert(!is_conv()); + assert(!is_length()); + assert(is_flags()); + return static_cast(tag_ & 0x1F); } private: - std::int8_t tag_; + uint8_t tag_; }; extern const ConvTag kTags[256]; -- cgit v1.2.3