Integrating fast_float to optionally replace strtod

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
       - name: make
         # Fail build if there are warnings
         # build with TLS just for compilation coverage
-        run: make -j4 all-with-unit-tests SERVER_CFLAGS='-Werror' BUILD_TLS=yes
+        run: make -j4 all-with-unit-tests SERVER_CFLAGS='-Werror' BUILD_TLS=yes USE_FAST_FLOAT=yes
       - name: test
         run: |
           sudo apt-get install tcl8.6 tclx
@@ -108,23 +108,30 @@ jobs:
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - name: make
-        run: make -j3 all-with-unit-tests SERVER_CFLAGS='-Werror'
+        # Build with additional upcoming features
+        run: make -j3 all-with-unit-tests SERVER_CFLAGS='-Werror' USE_FAST_FLOAT=yes
 
   build-32bit:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - name: make
+        # Fast float requires C++ 32-bit libraries to compile on 64-bit ubuntu
+        # machine i.e. "-cross" suffixed version. Cross-compiling c++ to 32-bit
+        # also requires multilib support for g++ compiler i.e. "-multilib"
+        # suffixed version of g++. g++-multilib generally includes libstdc++.
+        # *cross version as well, but it is also added explicitly just in case.
         run: |
-          sudo apt-get update && sudo apt-get install libc6-dev-i386
-          make -j4 SERVER_CFLAGS='-Werror' 32bit
+          sudo apt-get update
+          sudo apt-get install libc6-dev-i386 libstdc++-11-dev-i386-cross gcc-multilib g++-multilib
+          make -j4 SERVER_CFLAGS='-Werror' 32bit USE_FAST_FLOAT=yes
 
   build-libc-malloc:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
       - name: make
-        run: make -j4 SERVER_CFLAGS='-Werror' MALLOC=libc
+        run: make -j4 SERVER_CFLAGS='-Werror' MALLOC=libc USE_FAST_FLOAT=yes
 
   build-almalinux8-jemalloc:
     runs-on: ubuntu-latest
@@ -134,8 +141,8 @@ jobs:
 
       - name: make
         run: |
-          dnf -y install epel-release gcc make procps-ng which
-          make -j4 SERVER_CFLAGS='-Werror'
+          dnf -y install epel-release gcc gcc-c++ make procps-ng which
+          make -j4 SERVER_CFLAGS='-Werror' USE_FAST_FLOAT=yes
 
   format-yaml:
     runs-on: ubuntu-latest

.github/workflows/daily.yml

@@ -319,7 +319,7 @@ jobs:
           ref: ${{ env.GITHUB_HEAD_REF }}
       - name: make
         run: |
-          make BUILD_TLS=yes SERVER_CFLAGS='-Werror'
+          make BUILD_TLS=yes SERVER_CFLAGS='-Werror' USE_FAST_FLOAT=yes
       - name: testprep
         run: |
           sudo apt-get install tcl8.6 tclx tcl-tls

deps/Makefile

@@ -42,6 +42,7 @@ distclean:
 	-(cd jemalloc && [ -f Makefile ] && $(MAKE) distclean) > /dev/null || true
 	-(cd hdr_histogram && $(MAKE) clean) > /dev/null || true
 	-(cd fpconv && $(MAKE) clean) > /dev/null || true
+	-(cd fast_float_c_interface && $(MAKE) clean) > /dev/null || true
 	-(rm -f .make-*)
 
 .PHONY: distclean
@@ -116,3 +117,9 @@ jemalloc: .make-prerequisites
 	cd jemalloc && $(MAKE) lib/libjemalloc.a
 
 .PHONY: jemalloc
+
+fast_float_c_interface: .make-prerequisites
+	@printf '%b %b\n' $(MAKECOLOR)MAKE$(ENDCOLOR) $(BINCOLOR)$@$(ENDCOLOR)
+	cd fast_float_c_interface && $(MAKE)
+
+.PHONY: fast_float_c_interface

deps/README.md

@@ -6,6 +6,7 @@ should be provided by the operating system.
 * **linenoise** is a readline replacement. It is developed by the same authors of Valkey but is managed as a separated project and updated as needed.
 * **lua** is Lua 5.1 with minor changes for security and additional libraries.
 * **hdr_histogram** Used for per-command latency tracking histograms.
+* **fast_float** is a replacement for strtod to convert strings to floats efficiently. 
 
 How to upgrade the above dependencies
 ===
@@ -105,3 +106,17 @@ We use a customized version based on master branch commit e4448cf6d1cd08fff51981
 2. Copy updated files from newer version onto files in /hdr_histogram.
 3. Apply the changes from 1 above to the updated files.
 
+fast_float
+---
+The fast_float library provides fast header-only implementations for the C++ from_chars functions for `float` and `double` types as well as integer types.  These functions convert ASCII strings representing decimal values (e.g., `1.3e10`) into binary types. The functions are much faster than comparable number-parsing functions from existing C++ standard libraries.
+
+Specifically, `fast_float` provides the following function to parse floating-point numbers with a C++17-like syntax (the library itself only requires C++11):
+
+    template <typename T, typename UC = char, typename = FASTFLOAT_ENABLE_IF(is_supported_float_type<T>())>
+    from_chars_result_t<UC> from_chars(UC const *first, UC const *last, T &value, chars_format fmt = chars_format::general);
+
+To upgrade the library,
+1. Check out https://github.com/fastfloat/fast_float/tree/main
+2. cd fast_float
+3. Invoke "python3 ./script/amalgamate.py --output fast_float.h"
+4. Copy fast_float.h file to "deps/fast_float/".