/
string_methods.rb
409 lines (330 loc) · 9.52 KB
/
string_methods.rb
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require 'mock_redis/assertions'
class MockRedis
module StringMethods
include Assertions
include UtilityMethods
def append(key, value)
assert_stringy(key)
data[key] ||= ''
data[key] << value
data[key].length
end
def bitfield(*args)
if args.length < 4
raise Redis::CommandError, 'ERR wrong number of arguments for BITFIELD'
end
key = args.shift
output = []
overflow_method = 'wrap'
until args.empty?
command = args.shift.to_s
if command == 'overflow'
new_overflow_method = args.shift.to_s.downcase
unless %w[wrap sat fail].include? new_overflow_method
raise Redis::CommandError, 'ERR Invalid OVERFLOW type specified'
end
overflow_method = new_overflow_method
next
end
type, offset = args.shift(2)
is_signed = type.slice(0) == 'i'
type_size = type[1..-1].to_i
if (type_size > 64 && is_signed) || (type_size >= 64 && !is_signed)
raise Redis::CommandError,
'ERR Invalid bitfield type. Use something like i16 u8. ' \
'Note that u64 is not supported but i64 is.'
end
if offset.to_s[0] == '#'
offset = offset[1..-1].to_i * type_size
end
bits = []
type_size.times do |i|
bits.push(getbit(key, offset + i))
end
val = is_signed ? twos_complement_decode(bits) : bits.join('').to_i(2)
case command
when 'get'
output.push(val)
when 'set'
output.push(val)
set_bitfield(key, args.shift.to_i, is_signed, type_size, offset)
when 'incrby'
new_val = incr_bitfield(val, args.shift.to_i, is_signed, type_size, overflow_method)
set_bitfield(key, new_val, is_signed, type_size, offset) if new_val
output.push(new_val)
end
end
output
end
def decr(key)
decrby(key, 1)
end
def decrby(key, n)
incrby(key, -n)
end
def get(key)
key = key.to_s
assert_stringy(key)
data[key]
end
def getbit(key, offset)
assert_stringy(key)
offset_of_byte = offset / 8
offset_within_byte = offset % 8
# String#getbyte would be lovely, but it's not in 1.8.7.
byte = (data[key] || '').each_byte.drop(offset_of_byte).first
if byte
(byte & (2**7 >> offset_within_byte)) > 0 ? 1 : 0
else
0
end
end
def getrange(key, start, stop)
assert_stringy(key)
(data[key] || '')[start..stop]
end
def getset(key, value)
retval = get(key)
set(key, value)
retval
end
def incr(key)
incrby(key, 1)
end
def incrby(key, n)
assert_stringy(key)
unless can_incr?(data[key])
raise Redis::CommandError, 'ERR value is not an integer or out of range'
end
unless looks_like_integer?(n.to_s)
raise Redis::CommandError, 'ERR value is not an integer or out of range'
end
new_value = data[key].to_i + n.to_i
data[key] = new_value.to_s
# for some reason, redis-rb doesn't return this as a string.
new_value
end
def incrbyfloat(key, n)
assert_stringy(key)
unless can_incr_float?(data[key])
raise Redis::CommandError, 'ERR value is not a valid float'
end
unless looks_like_float?(n.to_s)
raise Redis::CommandError, 'ERR value is not a valid float'
end
new_value = data[key].to_f + n.to_f
data[key] = new_value.to_s
# for some reason, redis-rb doesn't return this as a string.
new_value
end
def mget(*keys)
assert_has_args(keys, 'mget')
keys.flatten!
keys.map do |key|
get(key) if stringy?(key)
end
end
def mapped_mget(*keys)
Hash[keys.zip(mget(*keys))]
end
def mset(*kvpairs)
assert_has_args(kvpairs, 'mset')
kvpairs = kvpairs.first if kvpairs.size == 1 && kvpairs.first.is_a?(Enumerable)
if kvpairs.length.odd?
raise Redis::CommandError, 'ERR wrong number of arguments for MSET'
end
kvpairs.each_slice(2) do |(k, v)|
set(k, v)
end
'OK'
end
def mapped_mset(hash)
mset(*hash.to_a.flatten)
end
def msetnx(*kvpairs)
assert_has_args(kvpairs, 'msetnx')
if kvpairs.each_slice(2).any? { |(k, _)| exists?(k) }
false
else
mset(*kvpairs)
true
end
end
def mapped_msetnx(hash)
msetnx(*hash.to_a.flatten)
end
def set(key, value, options = {})
key = key.to_s
return_true = false
options = options.dup
if options.delete(:nx)
if exists?(key)
return false
else
return_true = true
end
end
if options.delete(:xx)
if exists?(key)
return_true = true
else
return false
end
end
data[key] = value.to_s
duration = options.delete(:ex)
if duration
if duration == 0
raise Redis::CommandError, 'ERR invalid expire time in set'
end
expire(key, duration)
end
duration = options.delete(:px)
if duration
if duration == 0
raise Redis::CommandError, 'ERR invalid expire time in set'
end
pexpire(key, duration)
end
unless options.empty?
raise ArgumentError, "unknown keyword: #{options.keys[0]}"
end
return_true ? true : 'OK'
end
def setbit(key, offset, value)
assert_stringy(key, 'ERR bit is not an integer or out of range')
retval = getbit(key, offset)
str = data[key] || ''
offset_of_byte = offset / 8
offset_within_byte = offset % 8
if offset_of_byte >= str.bytesize
str = zero_pad(str, offset_of_byte + 1)
end
char_index = byte_index = offset_within_char = 0
str.each_char do |c|
if byte_index < offset_of_byte
char_index += 1
byte_index += c.bytesize
else
offset_within_char = byte_index - offset_of_byte
break
end
end
char = str[char_index]
char = char.chr if char.respond_to?(:chr) # ruby 1.8 vs 1.9
char_as_number = char.each_byte.reduce(0) do |a, byte|
(a << 8) + byte
end
bitmask_length = (char.bytesize * 8 - offset_within_char * 8 - offset_within_byte - 1)
bitmask = 1 << bitmask_length
if value.zero?
bitmask ^= 2**(char.bytesize * 8) - 1
char_as_number &= bitmask
else
char_as_number |= bitmask
end
str[char_index] = char_as_number.chr
data[key] = str
retval
end
def bitcount(key, start = 0, stop = -1)
assert_stringy(key)
str = data[key] || ''
count = 0
m1 = 0x5555555555555555
m2 = 0x3333333333333333
m4 = 0x0f0f0f0f0f0f0f0f
m8 = 0x00ff00ff00ff00ff
m16 = 0x0000ffff0000ffff
m32 = 0x00000000ffffffff
str.bytes.to_a[start..stop].each do |byte|
# Naive Hamming weight
c = byte
c = (c & m1) + ((c >> 1) & m1)
c = (c & m2) + ((c >> 2) & m2)
c = (c & m4) + ((c >> 4) & m4)
c = (c & m8) + ((c >> 8) & m8)
c = (c & m16) + ((c >> 16) & m16)
c = (c & m32) + ((c >> 32) & m32)
count += c
end
count
end
def setex(key, seconds, value)
if seconds <= 0
raise Redis::CommandError, 'ERR invalid expire time in setex'
else
set(key, value)
expire(key, seconds)
'OK'
end
end
def setnx(key, value)
if exists?(key)
false
else
set(key, value)
true
end
end
def setrange(key, offset, value)
assert_stringy(key)
value = value.to_s
old_value = (data[key] || '')
prefix = zero_pad(old_value[0...offset], offset)
data[key] = prefix + value + (old_value[(offset + value.length)..-1] || '')
data[key].length
end
def strlen(key)
assert_stringy(key)
(data[key] || '').bytesize
end
private
def stringy?(key)
data[key].nil? || data[key].is_a?(String)
end
def assert_stringy(key,
message = 'WRONGTYPE Operation against a key holding the wrong kind of value')
unless stringy?(key)
raise Redis::CommandError, message
end
end
def set_bitfield(key, value, is_signed, type_size, offset)
if is_signed
val_array = twos_complement_encode(value, type_size)
else
str = left_pad(value.to_i.abs.to_s(2), type_size)
val_array = str.split('').map(&:to_i)
end
val_array.each_with_index do |bit, i|
setbit(key, offset + i, bit)
end
end
def incr_bitfield(val, incrby, is_signed, type_size, overflow_method)
new_val = val + incrby
max = is_signed ? (2**(type_size - 1)) - 1 : (2**type_size) - 1
min = is_signed ? (-2**(type_size - 1)) : 0
size = 2**type_size
return new_val if (min..max).cover?(new_val)
case overflow_method
when 'fail'
new_val = nil
when 'sat'
new_val = new_val > max ? max : min
when 'wrap'
if is_signed
if new_val > max
remainder = new_val - (max + 1)
new_val = min + remainder.abs
else
remainder = new_val - (min - 1)
new_val = max - remainder.abs
end
else
new_val = new_val > max ? new_val % size : size - new_val.abs
end
end
new_val
end
end
end