From 8ee4f55caf7fefd147d28929a8876c08e2aaa04c Mon Sep 17 00:00:00 2001
From: Adriano Meligrana <68152031+Tortar@users.noreply.github.com>
Date: Sat, 14 Sep 2024 00:30:30 +0200
Subject: [PATCH] Remove algorithm L for single sample (#83)

---
 Project.toml                             |  2 +-
 src/UnweightedSamplingSingle.jl          | 50 +++++-------------------
 src/WeightedSamplingSingle.jl            | 39 ++----------------
 src/precompile.jl                        |  4 --
 test/benchmark/benchmark_tests.jl        |  2 +
 test/unweighted_sampling_single_tests.jl |  2 +-
 test/weighted_sampling_single_tests.jl   |  2 +-
 7 files changed, 18 insertions(+), 83 deletions(-)

diff --git a/Project.toml b/Project.toml
index 225de10..f91c937 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "StreamSampling"
 uuid = "ff63dad9-3335-55d8-95ec-f8139d39e468"
-version = "0.3.7"
+version = "0.3.8"
 
 [deps]
 Accessors = "7d9f7c33-5ae7-4f3b-8dc6-eff91059b697"
diff --git a/src/UnweightedSamplingSingle.jl b/src/UnweightedSamplingSingle.jl
index 1f56434..1d9b68d 100644
--- a/src/UnweightedSamplingSingle.jl
+++ b/src/UnweightedSamplingSingle.jl
@@ -1,42 +1,26 @@
 
-mutable struct SampleSingleAlgL{T,R} <: AbstractReservoirSampleSingle
-    state::Float64
-    seen_k::Int
-    skip_k::Int
-    const rng::R
-    value::T
-    SampleSingleAlgL{T,R}(state, seen_k, skip_k, rng) where {T,R} = new{T,R}(state, seen_k, skip_k, rng)
-end
-
 mutable struct SampleSingleAlgR{T,R} <: AbstractReservoirSampleSingle
     seen_k::Int
     skip_k::Int
     const rng::R
     value::T
-    SampleSingleAlgR{T,R}(seen_k, rng, value) where {T,R} = new{T,R}(seen_k, rng, value)
-    SampleSingleAlgR{T,R}(seen_k, rng) where {T,R} = new{T,R}(seen_k, rng)
+    SampleSingleAlgR{T,R}(rng) where {T,R} = new{T,R}(0, 0, rng)
+    SampleSingleAlgR{T,R}(seen_k, skip_k, rng, value) where {T,R} = new{T,R}(seen_k, skip_k, rng, value)
 end
 
-function value(s::SampleSingleAlgL)
-    s.state === 1.0 && return nothing
-    return s.value
-end
 function value(s::SampleSingleAlgR)
     s.seen_k === 0 && return nothing
     return s.value
 end
 
-function ReservoirSample(T, method::ReservoirAlgorithm = algR)
-    return ReservoirSample(Random.default_rng(), T, method, ms)
-end
-function ReservoirSample(rng::AbstractRNG, T, method::ReservoirAlgorithm = algR)
-    return ReservoirSample(rng, T, method, ms)
+function ReservoirSample(T, method::ReservoirAlgorithm = AlgR())
+    return ReservoirSample(Random.default_rng(), T, method, MutSample())
 end
-function ReservoirSample(rng::AbstractRNG, T, ::AlgL, ::MutSample)
-    return SampleSingleAlgL{T, typeof(rng)}(1.0, 0, 0, rng)
+function ReservoirSample(rng::AbstractRNG, T, method::ReservoirAlgorithm = AlgR())
+    return ReservoirSample(rng, T, method, MutSample())
 end
 function ReservoirSample(rng::AbstractRNG, T, ::AlgR, ::MutSample)
-    return SampleSingleAlgR{T, typeof(rng)}(0, 0, rng)
+    return SampleSingleAlgR{T, typeof(rng)}(rng)
 end
 
 @inline function update!(s::SampleSingleAlgR, el)
@@ -47,24 +31,7 @@ end
     end
     return s
 end
-@inline function update!(s::SampleSingleAlgL, el)
-    s.seen_k += 1
-    if s.skip_k > 0
-        s.skip_k -= 1
-    else
-        s.value = el
-        s.state *= rand(s.rng)
-        s.skip_k = -ceil(Int, randexp(s.rng)/log(1-s.state))
-    end
-    return s
-end
 
-function reset!(s::SampleSingleAlgL)
-    s.state = 1.0
-    s.seen_k = 0
-    s.skip_k = 0
-    return s
-end
 function reset!(s::SampleSingleAlgR)
     s.seen_k = 0
     s.skip_k = 0
@@ -75,7 +42,7 @@ function Base.merge(s1::AbstractReservoirSampleSingle, s2::AbstractReservoirSamp
     n1, n2 = n_seen(s1), n_seen(s2)
     n_tot = n1 + n2
     value = rand(s1.rng) < n1/n_tot ? s1.value : s2.value
-    return SampleSingleAlgR{typeof(value), typeof(s1.rng)}(n_tot, s1.rng, value)
+    return SampleSingleAlgR{typeof(value), typeof(s1.rng)}(n_tot, s1.skip_k + s2.skip_k, s1.rng, value)
 end
 
 function Base.merge!(s1::SampleSingleAlgR, s2::AbstractReservoirSampleSingle)
@@ -87,6 +54,7 @@ function Base.merge!(s1::SampleSingleAlgR, s2::AbstractReservoirSampleSingle)
         s1.value = s2.value
     end
     s1.seen_k = n_tot
+    s1.skip_k += s2.skip_k
     return s1
 end
 
diff --git a/src/WeightedSamplingSingle.jl b/src/WeightedSamplingSingle.jl
index d06f538..4eb3b4a 100644
--- a/src/WeightedSamplingSingle.jl
+++ b/src/WeightedSamplingSingle.jl
@@ -5,19 +5,6 @@ mutable struct RefVal{T}
     RefVal(value::T) where T = new{T}(value)
 end
 
-struct ImmutSampleSingleAlgARes{T,R} <: AbstractWeightedReservoirSampleSingle
-    state::Float64
-    rng::R
-    rvalue::RefVal{T}
-end
-mutable struct MutSampleSingleAlgARes{T,R} <: AbstractWeightedReservoirSampleSingle
-    state::Float64
-    const rng::R
-    value::T
-    MutSampleSingleAlgARes{T,R}(state, rng) where {T,R} = new{T,R}(state, rng)
-end
-const SampleSingleAlgARes = Union{ImmutSampleSingleAlgARes, MutSampleSingleAlgARes}
-
 struct ImmutSampleSingleAlgAExpJ{T,R} <: AbstractWeightedReservoirSampleSingle
     state::Float64
     skip_w::Float64
@@ -33,12 +20,6 @@ mutable struct MutSampleSingleAlgAExpJ{T,R} <: AbstractWeightedReservoirSampleSi
 end
 const SampleSingleAlgAExpJ = Union{ImmutSampleSingleAlgAExpJ, MutSampleSingleAlgAExpJ}
 
-function ReservoirSample(rng::R, T, ::AlgARes, ::MutSample) where {R<:AbstractRNG}
-    return MutSampleSingleAlgARes{T,R}(typemax(Float64), rng)
-end
-function ReservoirSample(rng::R, T, ::AlgARes, ::ImmutSample) where {R<:AbstractRNG}
-    return ImmutSampleSingleAlgARes(typemax(Float64), rng, RefVal{T}())
-end
 function ReservoirSample(rng::R, T, ::AlgAExpJ, ::MutSample) where {R<:AbstractRNG}
     return MutSampleSingleAlgAExpJ{T,R}(0.0, 0.0, rng)
 end
@@ -51,14 +32,6 @@ function value(s::AbstractWeightedReservoirSampleSingle)
     return get_val(s)
 end
 
-@inline function update!(s::SampleSingleAlgARes, el, w)
-    priority = randexp(s.rng)/w
-    if priority < s.state
-        @imm_reset s.state = priority
-        s = set_val(s, el)
-    end
-    return s
-end
 @inline function update!(s::SampleSingleAlgAExpJ, el, weight)
     @imm_reset s.state += weight
     if s.skip_w <= s.state
@@ -68,23 +41,19 @@ end
     return s
 end
 
-function reset!(s::MutSampleSingleAlgARes)
-    s.state = typemax(Float64)
-    return s
-end
 function reset!(s::MutSampleSingleAlgAExpJ)
     s.state = 0.0
     s.skip_w = 0.0
     return s
 end
 
-get_val(s::Union{ImmutSampleSingleAlgARes, ImmutSampleSingleAlgAExpJ}) = s.rvalue.value
-function set_val(s::Union{ImmutSampleSingleAlgARes, ImmutSampleSingleAlgAExpJ}, el)
+get_val(s::ImmutSampleSingleAlgAExpJ) = s.rvalue.value
+function set_val(s::ImmutSampleSingleAlgAExpJ, el)
     @reset s.rvalue.value = el
     return s
 end
-get_val(s::Union{MutSampleSingleAlgARes, MutSampleSingleAlgAExpJ}) = s.value
-function set_val(s::Union{MutSampleSingleAlgARes, MutSampleSingleAlgAExpJ}, el)
+get_val(s::MutSampleSingleAlgAExpJ) = s.value
+function set_val(s::MutSampleSingleAlgAExpJ, el)
     s.value = el
     return s
 end
diff --git a/src/precompile.jl b/src/precompile.jl
index 6b8c96c..bf1ac67 100644
--- a/src/precompile.jl
+++ b/src/precompile.jl
@@ -9,10 +9,6 @@ using PrecompileTools
     @compile_workload let
         rs = ReservoirSample(Int, algR)
         update_s_no_weights!(rs, iter)
-        rs = ReservoirSample(Int, algL)
-        update_s_no_weights!(rs, iter)
-        rs = ReservoirSample(Int, algARes)
-        update_s!(rs, iter)
         rs = ReservoirSample(Int, algAExpJ)
         update_s!(rs, iter)
         rs = ReservoirSample(Int, 2, algR)
diff --git a/test/benchmark/benchmark_tests.jl b/test/benchmark/benchmark_tests.jl
index e852310..6523ba7 100644
--- a/test/benchmark/benchmark_tests.jl
+++ b/test/benchmark/benchmark_tests.jl
@@ -4,6 +4,7 @@
     wv(el) = 1.0
     for m in (algR, algL, algRSWRSKIP)
         for size in (nothing, 10)
+            size == nothing && m === algL && continue
             size == nothing && m === algRSWRSKIP && continue
             s = size == nothing ? () : (size,)
             b = @benchmark itsample($rng, $iter, $s..., $m) evals=1
@@ -15,6 +16,7 @@
     end
     for m in (algARes, algAExpJ, algWRSWRSKIP)
         for size in (nothing, 10)
+            size == nothing && m === algARes && continue
             size == nothing && m === algWRSWRSKIP && continue
             s = size == nothing ? () : (size,)
             b = @benchmark itsample($rng, $iter, $wv, $s..., $m) evals=1
diff --git a/test/unweighted_sampling_single_tests.jl b/test/unweighted_sampling_single_tests.jl
index b6c5aee..afb63cc 100644
--- a/test/unweighted_sampling_single_tests.jl
+++ b/test/unweighted_sampling_single_tests.jl
@@ -1,6 +1,6 @@
 
 @testset "Unweighted sampling single tests" begin
-    @testset "method=$method" for method in (algL, algR)
+    @testset "method=$method" for method in (algR,)
         a, b = 1, 100
         z = itsample(a:b, method)
         @test a <= z <= b
diff --git a/test/weighted_sampling_single_tests.jl b/test/weighted_sampling_single_tests.jl
index 36be714..3d42243 100644
--- a/test/weighted_sampling_single_tests.jl
+++ b/test/weighted_sampling_single_tests.jl
@@ -1,6 +1,6 @@
 
 @testset "Weighted sampling single tests" begin
-    @testset "method=$method" for method in (algARes, algAExpJ)
+    @testset "method=$method" for method in (algAExpJ,)
     	wv(el) = 1.0
         a, b = 1, 100
         z = itsample(a:b, wv, method)