wehub-resource-sync
73 lines
1.6 KiB
Lua
73 lines
1.6 KiB
Lua
local buffer = require "string.buffer"
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local zlib = require "ffi-zlib"
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local yield = require("kong.tools.yield").yield
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local inflate_gzip = zlib.inflateGzip
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local deflate_gzip = zlib.deflateGzip
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local _M = {}
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-- lua-ffi-zlib allocated buffer of length +1,
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-- so use 64KB - 1 instead
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local GZIP_CHUNK_SIZE = 65535
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local function read_input_buffer(input_buffer)
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local count = 0
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local yield_size = GZIP_CHUNK_SIZE * 2
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return function(size)
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count = count + size
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if count > yield_size then
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count = 0
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yield()
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end
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local data = input_buffer:get(size)
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return data ~= "" and data or nil
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end
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end
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local function write_output_buffer(output_buffer)
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return function(data)
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return output_buffer:put(data)
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end
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end
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local function gzip_helper(inflate_or_deflate, input)
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local input_buffer = buffer.new(0):set(input)
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local output_buffer = buffer.new()
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local ok, err = inflate_or_deflate(read_input_buffer(input_buffer),
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write_output_buffer(output_buffer),
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GZIP_CHUNK_SIZE)
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if not ok then
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return nil, err
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end
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return output_buffer:get()
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end
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--- Gzip compress the content of a string
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-- @tparam string str the uncompressed string
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-- @return gz (string) of the compressed content, or nil, err to if an error occurs
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function _M.deflate_gzip(str)
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return gzip_helper(deflate_gzip, str)
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end
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--- Gzip decompress the content of a string
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-- @tparam string gz the Gzip compressed string
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-- @return str (string) of the decompressed content, or nil, err to if an error occurs
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function _M.inflate_gzip(gz)
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return gzip_helper(inflate_gzip, gz)
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end
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return _M
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