prosody
affaf6d08d26
util/hex.lua

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util/hex.lua @ 13186:affaf6d08d26

util.datamanager: Pad list writes to avoid crossing block boundaries By padding items so that they do not cross block boundaries, it becomes eaiser to delete whole blocks with fallocate() without cutting items in half, improving efficiency of such operations. Since list stores are used for message archives, where the most common deletion operation would be of the oldest entires, at the top of the file. With this, all blocks that contain items to be removed could be deleted without needing to read, delete and write out the whole file.
author Kim Alvefur <zash@zash.se>
date Wed, 07 Jun 2023 00:39:30 +0200
parent 12355:a0ff5c438e9d
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
6375
76d8907d5301 util.hex: Small util lib for converting to/from hex strings
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
1 local s_char = string.char;
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ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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2 local s_format = string.format;
ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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3 local s_gsub = string.gsub;
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442019e955dc util.hex: Normalize hex to lowercase and discard non-hex input
Kim Alvefur <zash@zash.se>
parents: 6545
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4 local s_lower = string.lower;
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ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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5
ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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6 local char_to_hex = {};
ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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7 local hex_to_char = {};
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76d8907d5301 util.hex: Small util lib for converting to/from hex strings
Matthew Wild <mwild1@gmail.com>
parents:
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8
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ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
diff changeset
9 do
ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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10 local char, hex;
ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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11 for i = 0,255 do
ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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12 char, hex = s_char(i), s_format("%02x", i);
ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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13 char_to_hex[char] = hex;
ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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14 hex_to_char[hex] = char;
ec566d7cd518 util.hex: Pedantic optimization, 1 table lookup per byte instead of 3 function calls makes it go faster
Kim Alvefur <zash@zash.se>
parents: 6384
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15 end
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76d8907d5301 util.hex: Small util lib for converting to/from hex strings
Matthew Wild <mwild1@gmail.com>
parents:
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16 end
76d8907d5301 util.hex: Small util lib for converting to/from hex strings
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
17
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3f4809d01783 util.hex: Use locals!
Kim Alvefur <zash@zash.se>
parents: 6375
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18 local function to(s)
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parents: 6384
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19 return (s_gsub(s, ".", char_to_hex));
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76d8907d5301 util.hex: Small util lib for converting to/from hex strings
Matthew Wild <mwild1@gmail.com>
parents:
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20 end
76d8907d5301 util.hex: Small util lib for converting to/from hex strings
Matthew Wild <mwild1@gmail.com>
parents:
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21
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3f4809d01783 util.hex: Use locals!
Kim Alvefur <zash@zash.se>
parents: 6375
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22 local function from(s)
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442019e955dc util.hex: Normalize hex to lowercase and discard non-hex input
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parents: 6545
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23 return (s_gsub(s_lower(s), "%X*(%x%x)%X*", hex_to_char));
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76d8907d5301 util.hex: Small util lib for converting to/from hex strings
Matthew Wild <mwild1@gmail.com>
parents:
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24 end
76d8907d5301 util.hex: Small util lib for converting to/from hex strings
Matthew Wild <mwild1@gmail.com>
parents:
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25
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Matthew Wild <mwild1@gmail.com>
parents: 6802
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26 return {
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parents: 6802
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27 encode = to, decode = from;
a0ff5c438e9d util.hex: Deprecate to/from in favour of encode/decode, for consistency!
Matthew Wild <mwild1@gmail.com>
parents: 6802
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28 -- COMPAT w/pre-0.12:
a0ff5c438e9d util.hex: Deprecate to/from in favour of encode/decode, for consistency!
Matthew Wild <mwild1@gmail.com>
parents: 6802
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29 to = to, from = from;
a0ff5c438e9d util.hex: Deprecate to/from in favour of encode/decode, for consistency!
Matthew Wild <mwild1@gmail.com>
parents: 6802
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30 };