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ac8ec004e5
If the required capacity would fit in an embded string, returns one. This can reduce malloc churn for code that use string buffers.
75 lines
2.1 KiB
Ruby
75 lines
2.1 KiB
Ruby
# frozen_string_literal: true
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require 'test/unit'
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require '-test-/string'
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require 'rbconfig/sizeof'
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class Test_StringCapacity < Test::Unit::TestCase
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def test_capacity_embedded
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assert_equal GC::INTERNAL_CONSTANTS[:BASE_SLOT_SIZE] - embed_header_size - 1, capa('foo')
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assert_equal max_embed_len, capa('1' * max_embed_len)
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assert_equal max_embed_len, capa('1' * (max_embed_len - 1))
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end
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def test_capacity_shared
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sym = ("a" * GC::INTERNAL_CONSTANTS[:BASE_SLOT_SIZE]).to_sym
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assert_equal 0, capa(sym.to_s)
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end
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def test_capacity_normal
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assert_equal max_embed_len + 1, capa('1' * (max_embed_len + 1))
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assert_equal max_embed_len + 100, capa('1' * (max_embed_len + 100))
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end
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def test_s_new_capacity
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assert_equal("", String.new(capacity: 1000))
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assert_equal(String, String.new(capacity: 1000).class)
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assert_equal(10_000 - 1, capa(String.new(capacity: 10_000))) # Real capa doesn't account for termlen
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assert_equal("", String.new(capacity: -1000))
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assert_equal(capa(String.new(capacity: -10000)), capa(String.new(capacity: -1000)))
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end
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def test_io_read
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s = String.new(capacity: 1000)
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open(__FILE__) {|f|f.read(1024*1024, s)}
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assert_equal(1024*1024, capa(s))
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open(__FILE__) {|f|s = f.read(1024*1024)}
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assert_operator(capa(s), :<=, s.bytesize+4096)
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end
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def test_literal_capacity
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s = eval(%{
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# frozen_string_literal: true
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"#{"a" * (max_embed_len + 1)}"
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})
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assert_equal(s.length, capa(s))
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end
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def test_capacity_frozen
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s = String.new("I am testing", capacity: 1000)
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s << "a" * GC::INTERNAL_CONSTANTS[:BASE_SLOT_SIZE]
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s.freeze
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assert_equal(s.length, capa(s))
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end
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def test_capacity_fstring
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s = String.new("a" * max_embed_len, capacity: max_embed_len * 3)
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s << "fstring capacity"
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s = -s
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assert_equal(s.length, capa(s))
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end
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private
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def capa(str)
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Bug::String.capacity(str)
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end
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def embed_header_size
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3 * RbConfig::SIZEOF['void*']
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end
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def max_embed_len
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GC::INTERNAL_CONSTANTS[:RVARGC_MAX_ALLOCATE_SIZE] - embed_header_size - 1
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end
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end
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