Refactor and move world_format.txt to world_format.md (#13504)

Co-authored-by: Muhammad Rifqi Priyo Susanto <muhammadrifqipriyosusanto@gmail.com>

CMakeLists.txt

@@ -283,7 +283,7 @@ install(FILES "doc/lua_api.md" DESTINATION "${DOCDIR}" COMPONENT "Docs")
 install(FILES "doc/client_lua_api.md" DESTINATION "${DOCDIR}" COMPONENT "Docs")
 install(FILES "doc/menu_lua_api.md" DESTINATION "${DOCDIR}" COMPONENT "Docs")
 install(FILES "doc/texture_packs.md" DESTINATION "${DOCDIR}" COMPONENT "Docs")
-install(FILES "doc/world_format.txt" DESTINATION "${DOCDIR}" COMPONENT "Docs")
+install(FILES "doc/world_format.md" DESTINATION "${DOCDIR}" COMPONENT "Docs")
 install(FILES "minetest.conf.example" DESTINATION "${EXAMPLE_CONF_DIR}")
 
 if(UNIX AND NOT APPLE)

doc/world_format.md

@@ -0,0 +1,627 @@
+# Minetest World Format 22...29
+
+This applies to a world format carrying the block serialization version
+22...27, used at least in
+* `0.4.dev-20120322` ... `0.4.dev-20120606` (22...23)
+* `0.4.0` (23)
+* 24 was never released as stable and existed for ~2 days
+* 27 was added in `0.4.15-dev`
+* 29 was added in `5.5.0-dev`
+
+The block serialization version does not fully specify every aspect of this
+format; if compliance with this format is to be checked, it needs to be
+done by detecting if the files and data indeed follows it.
+
+# Files
+
+Everything is contained in a directory, the name of which is freeform, but
+often serves as the name of the world.
+
+Currently, the authentication and ban data is stored on a per-world basis.
+It can be copied over from an old world to a newly created world.
+
+    World
+    ├── auth.txt ───── Authentication data
+    ├── auth.sqlite ── Authentication data (SQLite alternative)
+    ├── env_meta.txt ─ Environment metadata
+    ├── ipban.txt ──── Banned IPs/users
+    ├── map_meta.txt ─ Map metadata
+    ├── map.sqlite ─── Map data
+    ├── players ────── Player directory
+    │   │── player1 ── Player file
+    │   └── Foo ────── Player file
+    └── world.mt ───── World metadata
+
+## `auth.txt`
+
+Contains authentication data, one player per line.
+
+    <name>:<password hash>:<privilege1,...>
+
+Legacy format (until 0.4.12) of password hash is `<name><password>` SHA1'd,
+in base64.
+
+Format (since 0.4.13) of password hash is `#1#<salt>#<verifier>`, with the
+parts inside `<>` encoded in base64.
+
+`<verifier>` is an RFC 2945 compatible SRP verifier,
+of the given salt, password, and the player's name lowercased,
+using the 2048-bit group specified in RFC 5054 and the SHA-256 hash function.
+
+Example lines:
+* Player "celeron55", no password, privileges "interact" and "shout":
+    ```
+    celeron55::interact,shout
+    ```
+* Player "Foo", password "bar", privilege "shout", with a legacy password hash:
+    ```
+    foo:iEPX+SQWIR3p67lj/0zigSWTKHg:shout
+    ```
+* Player "Foo", password "bar", privilege "shout", with a 0.4.13 password hash:
+    ```
+    foo:#1#hPpy4O3IAn1hsNK00A6wNw#Kpu6rj7McsrPCt4euTb5RA5ltF7wdcWGoYMcRngwDi11cZhPuuR9i5Bo7o6A877TgcEwoc//HNrj9EjR/CGjdyTFmNhiermZOADvd8eu32FYK1kf7RMC0rXWxCenYuOQCG4WF9mMGiyTPxC63VAjAMuc1nCZzmy6D9zt0SIKxOmteI75pAEAIee2hx4OkSXRIiU4Zrxo1Xf7QFxkMY4x77vgaPcvfmuzom0y/fU1EdSnZeopGPvzMpFx80ODFx1P34R52nmVl0W8h4GNo0k8ZiWtRCdrJxs8xIg7z5P1h3Th/BJ0lwexpdK8sQZWng8xaO5ElthNuhO8UQx1l6FgEA:shout
+    ```
+* Player "bar", no password, no privileges:
+    ```
+    bar::
+    ```
+
+## `auth.sqlite`
+
+Contains authentication data as an SQLite database. This replaces auth.txt
+above when `auth_backend` is set to `sqlite3` in world.mt.
+
+This database contains two tables: `auth` and `user_privileges`:
+
+```sql
+CREATE TABLE `auth` (
+    `id` INTEGER PRIMARY KEY AUTOINCREMENT,
+    `name` VARCHAR(32) UNIQUE,
+    `password` VARCHAR(512),
+    `last_login` INTEGER
+);
+CREATE TABLE `user_privileges` (
+    `id` INTEGER,
+    `privilege` VARCHAR(32),
+    PRIMARY KEY (id, privilege),
+    CONSTRAINT fk_id FOREIGN KEY (id) REFERENCES auth (id) ON DELETE CASCADE
+);
+```
+
+The `name` and `password` fields of the auth table are the same as the auth.txt
+fields (with modern password hash). The `last_login` field is the last login
+time as a Unix time stamp.
+
+The `user_privileges` table contains one entry per privilege and player.
+A player with "interact" and "shout" privileges will have two entries, one
+with `privilege="interact"` and the second with `privilege="shout"`.
+
+## `env_meta.txt`
+
+Simple global environment variables.
+
+Example content:
+
+    game_time = 73471
+    time_of_day = 19118
+    EnvArgsEnd
+
+## `ipban.txt`
+
+Banned IP addresses and usernames.
+
+Example content:
+
+    123.456.78.9|foo
+    123.456.78.10|bar
+
+## `map_meta.txt`
+
+Simple global map variables.
+
+Example content:
+
+    seed = 7980462765762429666
+    [end_of_params]
+
+## `map.sqlite`
+
+Map data.
+
+See [Map File Format](#map-file-format) below.
+
+## `player1`, `Foo`
+
+Player data.
+
+Filename can be anything.
+
+See [Player File Format](#player-file-format) below.
+
+## `world.mt`
+
+World metadata.
+
+    gameid = mesetint             - name of the game
+    enable_damage = true          - whether damage is enabled or not
+    creative_mode = false         - whether creative mode is enabled or not
+    backend = sqlite3             - which DB backend to use for blocks (sqlite3, dummy, leveldb, redis, postgresql)
+    player_backend = sqlite3      - which DB backend to use for player data
+    readonly_backend = sqlite3    - optionally read-only seed DB (DB file _must_ be located in "readonly" subfolder)
+    auth_backend = files          - which DB backend to use for authentication data
+    mod_storage_backend = sqlite3 - which DB backend to use for mod storage
+    server_announce = false       - whether the server is publicly announced or not
+    load_mod_<mod> = false        - whether <mod> is to be loaded in this world
+
+For `load_mod_<mod>`, the possible values are:
+
+* `false` - Do not load the mod.
+* `true` - Load the mod from wherever it is found (may cause conflicts if the same mod appears also in some other place).
+* `mods/modpack/moddir` - Relative path to the mod
+    * Must be one of the following:
+        * `mods/`: mods in the user path's mods folder (ex. `/home/user/.minetest/mods`)
+        * `share/`: mods in the share's mods folder (ex. `/usr/share/minetest/mods`)
+        * `/path/to/env`: you can use absolute paths to mods inside folders specified with the `MINETEST_MOD_PATH` `env` variable.
+    * Other locations and absolute paths are not supported.
+    * Note that `moddir` is the directory name, not the mod name specified in mod.conf.
+
+`PostgreSQL` backend specific settings:
+
+    pgsql_connection = host=127.0.0.1 port=5432 user=mt_user password=mt_password dbname=minetest
+    pgsql_player_connection = (same parameters as above)
+    pgsql_readonly_connection = (same parameters as above)
+    pgsql_auth_connection = (same parameters as above)
+    pgsql_mod_storage_connection = (same parameters as above)
+
+`Redis` backend specific settings:
+
+    redis_address = 127.0.0.1  - Redis server address
+    redis_hash = foo           - Database hash
+    redis_port = 6379          - (optional) Connection port
+    redis_password = hunter2   - (optional) Server password
+
+# Player File Format
+
+Should be pretty self-explanatory.
+> **Note**: Position is in `nodes * 10`
+
+Example content:
+
+    hp = 11
+    name = celeron55
+    pitch = 39.77
+    position = (-5231.97,15,1961.41)
+    version = 1
+    yaw = 101.37
+    PlayerArgsEnd
+    List main 32
+    Item default:torch 13
+    Item default:pick_steel 1 50112
+    Item experimental:tnt
+    Item default:cobble 99
+    Item default:pick_stone 1 13104
+    Item default:shovel_steel 1 51838
+    Item default:dirt 61
+    Item default:rail 78
+    Item default:coal_lump 3
+    Item default:cobble 99
+    Item default:leaves 22
+    Item default:gravel 52
+    Item default:axe_steel 1 2045
+    Item default:cobble 98
+    Item default:sand 61
+    Item default:water_source 94
+    Item default:glass 2
+    Item default:mossycobble
+    Item default:pick_steel 1 64428
+    Item animalmaterials:bone
+    Item default:sword_steel
+    Item default:sapling
+    Item default:sword_stone 1 10647
+    Item default:dirt 99
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    EndInventoryList
+    List craft 9
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    EndInventoryList
+    List craftpreview 1
+    Empty
+    EndInventoryList
+    List craftresult 1
+    Empty
+    EndInventoryList
+    EndInventory
+
+# Map File Format
+
+Minetest maps consist of `MapBlock`s, chunks of 16x16x16 nodes.
+
+In addition to the bulk node data, `MapBlock`s stored on disk also contain
+other things.
+
+## History
+
+Initially, Minetest stored maps in a format called the "sectors" format.
+It was a directory/file structure like this:
+
+    sectors2/XXX/ZZZ/YYYY
+
+For example, the `MapBlock` at `(0, 1, -2)` was this file:
+
+    sectors2/000/ffd/0001
+
+Eventually Minetest outgrew this directory structure, as filesystems were
+struggling under the number of files and directories.
+
+Large servers seriously needed a new format, and thus the base of the
+current format was invented, suggested by celeron55 and implemented by
+JacobF.
+
+`SQLite3` was implemented. Blocks files were directly inserted as blobs
+in a single table, indexed by integer primary keys, which were hashed
+coordinates.
+
+Today, we know that `SQLite3` allows multiple primary keys (which would allow
+storing coordinates separately), but the format has been kept unchanged for
+that part.
+
+## `map.sqlite`
+`map.sqlite` is a `SQLite3` database, containing a single table, called
+`blocks`. It looks like this:
+
+```sql
+CREATE TABLE `blocks` (`pos` INT NOT NULL PRIMARY KEY, `data` BLOB);
+```
+
+## Position Hashing
+
+`pos` (a node position hash) is created from the three coordinates of a
+`MapBlock` using this algorithm, defined here in Python:
+
+```python
+def getBlockAsInteger(p):
+    return int64(p[2]*16777216 + p[1]*4096 + p[0])
+
+def int64(u):
+    while u >= 2**63:
+        u -= 2**64
+    while u <= -2**63:
+        u += 2**64
+    return u
+```
+
+It can be converted the other way by using this code:
+
+```python
+def getIntegerAsBlock(i):
+    x = unsignedToSigned(i % 4096, 2048)
+    i = int((i - x) / 4096)
+    y = unsignedToSigned(i % 4096, 2048)
+    i = int((i - y) / 4096)
+    z = unsignedToSigned(i % 4096, 2048)
+    return x,y,z
+
+def unsignedToSigned(i, max_positive):
+    if i < max_positive:
+        return i
+    else:
+        return i - 2*max_positive
+```
+
+## Blob
+
+The blob is the data that would have otherwise gone into the file.
+
+See below for description.
+
+# MapBlock Serialization Format
+
+> **Notes**:
+>  * NOTE: Byte order is MSB first (big-endian).
+>  * NOTE: Zlib data is in such a format that Python's `zlib` at least can
+>          directly decompress.
+>  * NOTE: Since version 29 zstd is used instead of zlib. In addition, the entire
+>          block is first serialized and then compressed (except the version byte).
+
+`u8` version
+* map format version number, see serialization.h for the latest number
+
+`u8` flags
+* Flag bitmasks:
+    * `0x01`: `is_underground`: Should be set to 0 if there will be no light
+      obstructions above the block. If/when sunlight of a block is updated
+      and there is no block above it, this value is checked for determining
+      whether sunlight comes from the top.
+
+    * `0x02`: `day_night_differs`: Whether the lighting of the block is different
+      on day and night. Only blocks that have this bit set are updated when
+      day transforms to night.
+
+    * `0x04`: `lighting_expired`: Not used in version 27 and above. If true,
+      lighting is invalid and should be updated. If you can't calculate
+      lighting in your generator properly, you could try setting this 1 to
+      everything and setting the uppermost block in every sector as
+      `is_underground=0`. It most likely won't work properly.
+
+    * `0x08`: `generated`: True if the block has been generated. If false, block
+      is mostly filled with `CONTENT_IGNORE` and is likely to contain e.g. parts
+      of trees of neighboring blocks.
+
+`u16` lighting_complete
+* Added in version 27.
+
+* This contains 12 flags, each of them corresponds to a direction.
+
+* Indicates if the light is correct at the sides of a map block.
+  Lighting may not be correct if the light changed, but a neighbor
+  block was not loaded at that time.
+  If these flags are false, Minetest will automatically recompute light
+  when both this block and its required neighbor are loaded.
+
+* The bit order is:
+  nothing,  nothing,  nothing,  nothing,
+  night X-, night Y-, night Z-, night Z+, night Y+, night X+,
+  day X-,   day Y-,   day Z-,   day Z+,   day Y+,   day X+.
+  Where 'day' is for the day light bank, 'night' is for the night
+  light bank.
+  The 'nothing' bits should be always set, as they will be used
+  to indicate if direct sunlight spreading is finished.
+
+* Example: if the block at `(0, 0, 0)` has `lighting_complete = 0b1111111111111110`,
+  Minetest will correct lighting in the day light bank when the block at
+  `(1, 0, 0)` is also loaded.
+
+Timestamp and node ID mappings were introduced in map format version 29.
+* `u32` timestamp
+    * Timestamp when last saved, as seconds from starting the game.
+    * `0xffffffff` = invalid/unknown timestamp, nothing should be done with the time
+                     difference when loaded
+
+* `u8` `name_id_mapping_version`
+    * Should be zero for map format version 29.
+  
+* `u16` `num_name_id_mappings`
+    * foreach `num_name_id_mappings`:
+        * `u16` `id`
+        * `u16` `name_len`
+        * `u8[name_len]` `name`
+
+`u8` content_width
+* Number of bytes in the content (`param0`) fields of nodes
+* 1 byte before map format version 24, 2 bytes since
+
+`u8` params_width
+* Number of bytes used for parameters per node
+* Always 2
+
+## Node Data
+> **Note**: Zlib-compressed before map format version 29
+
+* If `content_width` is 1:
+    * `u8[4096]`: `param0` fields
+    * `u8[4096]`: `param1` fields
+    * `u8[4096]`: `param2` fields
+
+* If `content_width` is 2:
+    * `u16[4096]`: `param0` fields
+    * `u8[4096]`: `param1` fields
+    * `u8[4096]`: `param2` fields
+
+* The location of a node in each of those arrays is `(z*16*16 + y*16 + x)`.
+
+### Node Metadata List
+> **Note**: Zlib-compressed before map version format 29
+* Before map format version 23:
+    * `u16` version (=1)
+    * `u16` count of metadata
+    * foreach count:
+        * `u16` position (`(p.Z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + p.Y*MAP_BLOCKSIZE + p.X)`)
+        * `u16` type_id
+        * `u16` content_size
+        * `u8[content_size]` content of metadata. Format depends on `type_id`, see below.
+
+* Since map format version 23:
+    * `u8` version
+        > **Note**: Type was `u16` before map format version 23
+        * = 1 before map format version 28
+        * = 2 since map format version 28
+    * `u16` count of metadata
+    * foreach count:
+        * `u16` `position` (`(p.Z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + p.Y*MAP_BLOCKSIZE + p.X)`)
+        * `u32` `num_vars`
+        * foreach `num_vars`:
+            * `u16` `key_len`
+            * `u8[key_len]` `key`
+            * `u32 val_len`
+            * `u8[val_len]` `value`
+            * `u8` `is_private`
+            * only since map format version 2. 0 = not private, 1 = private
+        * serialized inventory
+
+## Node Timers
+* Map format version 23:
+    * `u8` unused version (always 0)
+
+* Map format version 24:
+    > **Note**: Not released as stable
+    * `u8` `nodetimer_version`
+    * if `nodetimer_version` == 1:
+        * `u16` `num_of_timers`
+        * foreach `num_of_timers`:
+            * `u16` timer position (`(z*16*16 + y*16 + x)`)
+            * `s32` timeout * 1000
+            * `s32` elapsed * 1000
+
+* Since map format version 25:
+    * `u8` length of the data of a single timer (always 2+4+4=10)
+    * `u16` `num_of_timers`
+    * foreach `num_of_timers`:
+        * `u16` timer position (`(z*16*16 + y*16 + x)`)
+        * `s32` timeout * 1000
+        * `s32` elapsed * 1000
+
+`u8` static object version:
+* Always 0
+
+`u16` `static_object_count`
+
+foreach `static_object_count`:
+* `u8` type (object type-id)
+* `s32` `pos_x_nodes` * 10000
+* `s32` `pos_y_nodes` * 10000
+* `s32` `pos_z_nodes` * 10000
+* `u16` `data_size`
+* `u8[data_size]` `data`
+
+Before map format version 29:
+* `u32` `timestamp`
+    * Same meaning as the timestamp further up
+
+* `u8` `name-id-mapping` version
+    * Always 0
+
+* `u16` `num_name_id_mappings`
+    * foreach `num_name_id_mappings`:
+        * `u16` `id`
+        * `u16` `name_len`
+        * `u8[name_len]` `name`
+
+End of File (EOF).
+
+# Format of Nodes
+
+A node is composed of the `u8` fields `param0`, `param1` and `param2`.
+
+Before map format version 24:
+* The content id of a node is determined as so:
+    * If `param0` < `0x80`, `content_id = param0`
+    * Otherwise, `content_id = (param0<<4) + (param2>>4)`
+
+Since map format version 24:
+* The content id of a node is `param0`.
+
+The purpose of `param1` and `param2` depend on the definition of the node.
+
+# Name-ID-Mapping
+
+The mapping maps node content IDs to node names.
+
+# Node Metadata Format (Before Map Format Version 23)
+
+The node metadata is serialized depending on the `type_id` field.
+
+`1`: Generic metadata
+* serialized inventory
+* `u32` `len`
+* `u8[len]` `text`
+* `u16` `len`
+* `u8[len]` `owner`
+* `u16` `len`
+* `u8[len]` `infotext`
+* `u16` `len`
+* `u8[len]` inventory drawspec
+* `u8` `allow_text_input` (bool)
+* `u8` `removal_disabled` (bool)
+* `u8` `enforce_owner` (bool)
+* `u32` `num_vars`
+* foreach `num_vars`:
+    * `u16` `len`
+    * `u8[len]` `name`
+    * `u32` `len`
+    * `u8[len]` `value`
+
+`14`: Sign metadata
+* `u16` `text_len`
+* `u8[text_len]` `text`
+
+`15`: Chest metadata
+* serialized inventory
+
+`16`: Furnace metadata
+* To be determined
+
+`17`: Locked Chest metadata
+* `u16` `len`
+* `u8[len]` `owner`
+* serialized inventory
+
+# Static Objects
+
+Static objects are persistent freely moving objects in the world.
+
+Object types:
+`1`: Test object
+`7`: LuaEntity:
+* `u8` `compatibility_byte` (always 1)
+* `u16` `len`
+* `u8[len]` entity name
+* `u32` `len`
+* `u8[len]` static data
+* `s16` `hp`
+* `s32` velocity.x * 10000
+* `s32` velocity.y * 10000
+* `s32` velocity.z * 10000
+* `s32` yaw * 1000
+
+Since protocol version 37:
+* `u8` `version2` (=1)
+* `s32` pitch * 1000
+* `s32` roll * 1000
+
+# Itemstring Format
+
+Examples:
+* `'default:dirt 5'`
+* `'default:pick_wood 21323'`
+* `'"default:apple" 2'`
+* `'default:apple'`
+
+Older formats:
+* `'node "default:dirt" 5'`
+* `'NodeItem default:dirt 5'`
+* `'ToolItem WPick 21323'`
+
+The wear value in tools is 0...65535.
+
+# Inventory Serialization Format
+
+* The inventory serialization format is line-based.
+* The newline character used is `\n`
+* The end condition of a serialized inventory is always `EndInventory\n`
+* All the slots in a list must always be serialized.
+
+## Example
+
+    List foo 4
+    Item default:sapling
+    Item default:sword_stone 1 10647
+    Item default:dirt 99
+    Empty
+    EndInventoryList
+    List bar 9
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    Empty
+    EndInventoryList
+    EndInventory

doc/world_format.txt

@@ -1,598 +0,0 @@
-=============================
-Minetest World Format 22...29
-=============================
-
-This applies to a world format carrying the block serialization version
-22...27, used at least in
-- 0.4.dev-20120322 ... 0.4.dev-20120606 (22...23)
-- 0.4.0 (23)
-- 24 was never released as stable and existed for ~2 days
-- 27 was added in 0.4.15-dev
-- 29 was added in 5.5.0-dev
-
-The block serialization version does not fully specify every aspect of this
-format; if compliance with this format is to be checked, it needs to be
-done by detecting if the files and data indeed follows it.
-
-Files
-======
-Everything is contained in a directory, the name of which is freeform, but
-often serves as the name of the world.
-
-Currently the authentication and ban data is stored on a per-world basis.
-It can be copied over from an old world to a newly created world.
-
-World
-|-- auth.txt ----- Authentication data
-|-- auth.sqlite -- Authentication data (SQLite alternative)
-|-- env_meta.txt - Environment metadata
-|-- ipban.txt ---- Banned ips/users
-|-- map_meta.txt - Map metadata
-|-- map.sqlite --- Map data
-|-- players ------ Player directory
-|   |-- player1 -- Player file
-|   '-- Foo ------ Player file
-`-- world.mt ----- World metadata
-
-auth.txt
----------
-Contains authentication data, player per line.
-  <name>:<password hash>:<privilege1,...>
-
-Legacy format (until 0.4.12) of password hash is <name><password> SHA1'd,
-in the base64 encoding.
-
-Format (since 0.4.13) of password hash is #1#<salt>#<verifier>, with the
-parts inside <> encoded in the base64 encoding.
-<verifier> is an RFC 2945 compatible SRP verifier,
-of the given salt, password, and the player's name lowercased,
-using the 2048-bit group specified in RFC 5054 and the SHA-256 hash function.
-
-Example lines:
-- Player "celeron55", no password, privileges "interact" and "shout":
-    celeron55::interact,shout
-- Player "Foo", password "bar", privilege "shout", with a legacy password hash:
-    foo:iEPX+SQWIR3p67lj/0zigSWTKHg:shout
-- Player "Foo", password "bar", privilege "shout", with a 0.4.13 pw hash:
-    foo:#1#hPpy4O3IAn1hsNK00A6wNw#Kpu6rj7McsrPCt4euTb5RA5ltF7wdcWGoYMcRngwDi11cZhPuuR9i5Bo7o6A877TgcEwoc//HNrj9EjR/CGjdyTFmNhiermZOADvd8eu32FYK1kf7RMC0rXWxCenYuOQCG4WF9mMGiyTPxC63VAjAMuc1nCZzmy6D9zt0SIKxOmteI75pAEAIee2hx4OkSXRIiU4Zrxo1Xf7QFxkMY4x77vgaPcvfmuzom0y/fU1EdSnZeopGPvzMpFx80ODFx1P34R52nmVl0W8h4GNo0k8ZiWtRCdrJxs8xIg7z5P1h3Th/BJ0lwexpdK8sQZWng8xaO5ElthNuhO8UQx1l6FgEA:shout
-- Player "bar", no password, no privileges:
-    bar::
-
-auth.sqlite
-------------
-Contains authentification data as an SQLite database. This replaces auth.txt
-above when auth_backend is set to "sqlite3" in world.mt .
-
-This database contains two tables "auth" and "user_privileges":
-
-CREATE TABLE `auth` (
-  `id` INTEGER PRIMARY KEY AUTOINCREMENT,
-  `name` VARCHAR(32) UNIQUE,
-  `password` VARCHAR(512),
-  `last_login` INTEGER
-);
-CREATE TABLE `user_privileges` (
-  `id` INTEGER,
-  `privilege` VARCHAR(32),
-  PRIMARY KEY (id, privilege)
-  CONSTRAINT fk_id FOREIGN KEY (id) REFERENCES auth (id) ON DELETE CASCADE
-);
-
-The "name" and "password" fields of the auth table are the same as the auth.txt
-fields (with modern password hash). The "last_login" field is the last login
-time as a unix time stamp.
-
-The "user_privileges" table contains one entry per privilege and player.
-A player with "interact" and "shout" privileges will have two entries, one
-with privilege="interact" and the second with privilege="shout".
-
-env_meta.txt
--------------
-Simple global environment variables.
-Example content (added indentation):
-  game_time = 73471
-  time_of_day = 19118
-  EnvArgsEnd
-
-ipban.txt
-----------
-Banned IP addresses and usernames.
-Example content (added indentation):
-  123.456.78.9|foo
-  123.456.78.10|bar
-
-map_meta.txt
--------------
-Simple global map variables.
-Example content (added indentation):
-  seed = 7980462765762429666
-  [end_of_params]
-
-map.sqlite
------------
-Map data.
-See Map File Format below.
-
-player1, Foo
--------------
-Player data.
-Filename can be anything.
-See Player File Format below.
-
-world.mt
----------
-World metadata.
-Example content (added indentation and - explanations):
-  gameid = mesetint             - name of the game
-  enable_damage = true          - whether damage is enabled or not
-  creative_mode = false         - whether creative mode is enabled or not
-  backend = sqlite3             - which DB backend to use for blocks (sqlite3, dummy, leveldb, redis, postgresql)
-  player_backend = sqlite3      - which DB backend to use for player data
-  readonly_backend = sqlite3    - optionally readonly seed DB (DB file _must_ be located in "readonly" subfolder)
-  auth_backend = files          - which DB backend to use for authentication data
-  mod_storage_backend = sqlite3 - which DB backend to use for mod storage
-  server_announce = false       - whether the server is publicly announced or not
-  load_mod_<mod> = false        - whether <mod> is to be loaded in this world
-
-For load_mod_<mod>, the possible values are:
-
-* `false` - Do not load the mod.
-* `true` - Load the mod from wherever it is found (may cause conflicts if the same mod appears also in some other place).
-* `mods/modpack/moddir` - Relative path to the mod
-    * Must be one of the following:
-        * `mods/`: mods in the user path's mods folder (ex `/home/user/.minetest/mods`)
-        * `share/`: mods in the share's mods folder (ex: `/usr/share/minetest/mods`)
-        * `/path/to/env`: you can use absolute paths to mods inside folders specified with the `MINETEST_MOD_PATH` env variable.
-    * Other locations and absolute paths are not supported
-    * Note that `moddir` is the directory name, not the mod name specified in mod.conf.
-
-PostgreSQL backend specific settings:
-  pgsql_connection = host=127.0.0.1 port=5432 user=mt_user password=mt_password dbname=minetest
-  pgsql_player_connection = (same parameters as above)
-  pgsql_readonly_connection = (same parameters as above)
-  pgsql_auth_connection = (same parameters as above)
-  pgsql_mod_storage_connection = (same parameters as above)
-
-Redis backend specific settings:
-  redis_address = 127.0.0.1  - Redis server address
-  redis_hash = foo           - Database hash
-  redis_port = 6379          - (optional) connection port
-  redis_password = hunter2   - (optional) server password
-
-
-Player File Format
-===================
-
-- Should be pretty self-explanatory.
-- Note: position is in nodes * 10
-
-Example content (added indentation):
-  hp = 11
-  name = celeron55
-  pitch = 39.77
-  position = (-5231.97,15,1961.41)
-  version = 1
-  yaw = 101.37
-  PlayerArgsEnd
-  List main 32
-  Item default:torch 13
-  Item default:pick_steel 1 50112
-  Item experimental:tnt
-  Item default:cobble 99
-  Item default:pick_stone 1 13104
-  Item default:shovel_steel 1 51838
-  Item default:dirt 61
-  Item default:rail 78
-  Item default:coal_lump 3
-  Item default:cobble 99
-  Item default:leaves 22
-  Item default:gravel 52
-  Item default:axe_steel 1 2045
-  Item default:cobble 98
-  Item default:sand 61
-  Item default:water_source 94
-  Item default:glass 2
-  Item default:mossycobble
-  Item default:pick_steel 1 64428
-  Item animalmaterials:bone
-  Item default:sword_steel
-  Item default:sapling
-  Item default:sword_stone 1 10647
-  Item default:dirt 99
-  Empty
-  Empty
-  Empty
-  Empty
-  Empty
-  Empty
-  Empty
-  Empty
-  EndInventoryList
-  List craft 9
-  Empty
-  Empty
-  Empty
-  Empty
-  Empty
-  Empty
-  Empty
-  Empty
-  Empty
-  EndInventoryList
-  List craftpreview 1
-  Empty
-  EndInventoryList
-  List craftresult 1
-  Empty
-  EndInventoryList
-  EndInventory
-
-Map File Format
-================
-
-Minetest maps consist of MapBlocks, chunks of 16x16x16 nodes.
-
-In addition to the bulk node data, MapBlocks stored on disk also contain
-other things.
-
-History
---------
-We need a bit of history in here. Initially Minetest stored maps in a
-format called the "sectors" format. It was a directory/file structure like
-this:
-  sectors2/XXX/ZZZ/YYYY
-For example, the MapBlock at (0,1,-2) was this file:
-  sectors2/000/ffd/0001
-
-Eventually Minetest outgrow this directory structure, as filesystems were
-struggling under the amount of files and directories.
-
-Large servers seriously needed a new format, and thus the base of the
-current format was invented, suggested by celeron55 and implemented by
-JacobF.
-
-SQLite3 was slammed in, and blocks files were directly inserted as blobs
-in a single table, indexed by integer primary keys, oddly mangled from
-coordinates.
-
-Today we know that SQLite3 allows multiple primary keys (which would allow
-storing coordinates separately), but the format has been kept unchanged for
-that part. So, this is where it has come.
-</history>
-
-So here goes
--------------
-map.sqlite is an sqlite3 database, containing a single table, called
-"blocks". It looks like this:
-
-  CREATE TABLE `blocks` (`pos` INT NOT NULL PRIMARY KEY,`data` BLOB);
-
-The key
---------
-"pos" is created from the three coordinates of a MapBlock using this
-algorithm, defined here in Python:
-
-  def getBlockAsInteger(p):
-      return int64(p[2]*16777216 + p[1]*4096 + p[0])
-
-  def int64(u):
-      while u >= 2**63:
-          u -= 2**64
-      while u <= -2**63:
-          u += 2**64
-      return u
-
-It can be converted the other way by using this code:
-
-  def getIntegerAsBlock(i):
-      x = unsignedToSigned(i % 4096, 2048)
-      i = int((i - x) / 4096)
-      y = unsignedToSigned(i % 4096, 2048)
-      i = int((i - y) / 4096)
-      z = unsignedToSigned(i % 4096, 2048)
-      return x,y,z
-
-  def unsignedToSigned(i, max_positive):
-      if i < max_positive:
-          return i
-      else:
-          return i - 2*max_positive
-
-The blob
----------
-The blob is the data that would have otherwise gone into the file.
-
-See below for description.
-
-MapBlock serialization format
-==============================
-NOTE: Byte order is MSB first (big-endian).
-NOTE: Zlib data is in such a format that Python's zlib at least can
-      directly decompress.
-NOTE: Since version 29 zstd is used instead of zlib. In addition the entire
-      block is first serialized and then compressed (except the version byte).
-
-u8 version
-- map format version number, see serialization.h for the latest number
-
-u8 flags
-- Flag bitmasks:
-  - 0x01: is_underground: Should be set to 0 if there will be no light
-    obstructions above the block. If/when sunlight of a block is updated
-    and there is no block above it, this value is checked for determining
-    whether sunlight comes from the top.
-  - 0x02: day_night_differs: Whether the lighting of the block is different
-    on day and night. Only blocks that have this bit set are updated when
-    day transforms to night.
-  - 0x04: lighting_expired: Not used in version 27 and above. If true,
-    lighting is invalid and should be updated.  If you can't calculate
-    lighting in your generator properly, you could try setting this 1 to
-    everything and setting the uppermost block in every sector as
-    is_underground=0. I am quite sure it doesn't work properly, though.
-  - 0x08: generated: True if the block has been generated. If false, block
-    is mostly filled with CONTENT_IGNORE and is likely to contain eg. parts
-    of trees of neighboring blocks.
-
-u16 lighting_complete
-- Added in version 27.
-- This contains 12 flags, each of them corresponds to a direction.
-- Indicates if the light is correct at the sides of a map block.
-  Lighting may not be correct if the light changed, but a neighbor
-  block was not loaded at that time.
-  If these flags are false, Minetest will automatically recompute light
-  when both this block and its required neighbor are loaded.
-- The bit order is:
-  nothing,  nothing,  nothing,  nothing,
-  night X-, night Y-, night Z-, night Z+, night Y+, night X+,
-  day X-,   day Y-,   day Z-,   day Z+,   day Y+,   day X+.
-  Where 'day' is for the day light bank, 'night' is for the night
-  light bank.
-  The 'nothing' bits should be always set, as they will be used
-  to indicate if direct sunlight spreading is finished.
-- Example: if the block at (0, 0, 0) has
-  lighting_complete = 0b1111111111111110,
-  then Minetest will correct lighting in the day light bank when
-  the block at (1, 0, 0) is also loaded.
-
-if map format version >= 29:
-  u32 timestamp
-  - Timestamp when last saved, as seconds from starting the game.
-  - 0xffffffff = invalid/unknown timestamp, nothing should be done with the time
-                 difference when loaded
-
-  u8 name_id_mapping_version
-  - Should be zero for map format version 29.
-
-  u16 num_name_id_mappings
-  foreach num_name_id_mappings
-    u16 id
-    u16 name_len
-    u8[name_len] name
-if map format version < 29:
-  -- Nothing right here, timestamp and node id mappings are serialized later
-
-u8 content_width
-- Number of bytes in the content (param0) fields of nodes
-if map format version <= 23:
-    - Always 1
-if map format version >= 24:
-    - Always 2
-
-u8 params_width
-- Number of bytes used for parameters per node
-- Always 2
-
-node data (zlib-compressed if version < 29):
-if content_width == 1:
-    - content:
-      u8[4096]: param0 fields
-      u8[4096]: param1 fields
-      u8[4096]: param2 fields
-if content_width == 2:
-    - content:
-      u16[4096]: param0 fields
-      u8[4096]: param1 fields
-      u8[4096]: param2 fields
-- The location of a node in each of those arrays is (z*16*16 + y*16 + x).
-
-node metadata list (zlib-compressed if version < 29):
-- content:
-  if map format version <= 22:
-    u16 version (=1)
-    u16 count of metadata
-    foreach count:
-      u16 position (p.Z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + p.Y*MAP_BLOCKSIZE + p.X)
-      u16 type_id
-      u16 content_size
-      u8[content_size] content of metadata. Format depends on type_id, see below.
-  if map format version >= 23:
-    u8 version -- Note: type was u16 for map format version <= 22
-      -- = 1 for map format version < 28
-      -- = 2 since map format version 28
-    u16 count of metadata
-    foreach count:
-      u16 position (p.Z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + p.Y*MAP_BLOCKSIZE + p.X)
-      u32 num_vars
-      foreach num_vars:
-        u16 key_len
-        u8[key_len] key
-        u32 val_len
-        u8[val_len] value
-        u8 is_private -- only for version >= 2. 0 = not private, 1 = private
-      serialized inventory
-
-- Node timers
-if map format version == 23:
-  u8 unused version (always 0)
-if map format version == 24: (NOTE: Not released as stable)
-  u8 nodetimer_version
-  if nodetimer_version == 0:
-    (nothing else)
-  if nodetimer_version == 1:
-    u16 num_of_timers
-    foreach num_of_timers:
-      u16 timer position (z*16*16 + y*16 + x)
-      s32 timeout*1000
-      s32 elapsed*1000
-if map format version >= 25:
-  -- Nothing right here, node timers are serialized later
-
-u8 static object version:
-- Always 0
-
-u16 static_object_count
-
-foreach static_object_count:
-  u8 type (object type-id)
-  s32 pos_x_nodes * 10000
-  s32 pos_y_nodes * 10000
-  s32 pos_z_nodes * 10000
-  u16 data_size
-  u8[data_size] data
-
-if map format version < 29:
-  u32 timestamp
-  - Same meaning as the timestamp further up
-
-  u8 name-id-mapping version
-  - Always 0
-
-  u16 num_name_id_mappings
-  foreach num_name_id_mappings
-    u16 id
-    u16 name_len
-    u8[name_len] name
-
-- Node timers
-if map format version >= 25:
-  u8 length of the data of a single timer (always 2+4+4=10)
-  u16 num_of_timers
-  foreach num_of_timers:
-    u16 timer position (z*16*16 + y*16 + x)
-    s32 timeout*1000
-    s32 elapsed*1000
-
-EOF.
-
-Format of nodes
-----------------
-A node is composed of the u8 fields param0, param1 and param2.
-
-if map format version <= 23:
-    The content id of a node is determined as so:
-    - If param0 < 0x80,
-        content_id = param0
-    - Otherwise
-        content_id = (param0<<4) + (param2>>4)
-if map format version >= 24:
-    The content id of a node is param0.
-
-The purpose of param1 and param2 depend on the definition of the node.
-
-The name-id-mapping
---------------------
-The mapping maps node content ids to node names.
-
-Node metadata format for map format versions <= 22
----------------------------------------------------
-The node metadata are serialized depending on the type_id field.
-
-1: Generic metadata
-  serialized inventory
-  u32 len
-  u8[len] text
-  u16 len
-  u8[len] owner
-  u16 len
-  u8[len] infotext
-  u16 len
-  u8[len] inventory drawspec
-  u8 allow_text_input (bool)
-  u8 removal_disabled (bool)
-  u8 enforce_owner (bool)
-  u32 num_vars
-  foreach num_vars
-    u16 len
-    u8[len] name
-    u32 len
-    u8[len] value
-
-14: Sign metadata
-  u16 text_len
-  u8[text_len] text
-
-15: Chest metadata
-  serialized inventory
-
-16: Furnace metadata
-  TBD
-
-17: Locked Chest metadata
-  u16 len
-  u8[len] owner
-  serialized inventory
-
-Static objects
----------------
-Static objects are persistent freely moving objects in the world.
-
-Object types:
-1: Test object
-7: LuaEntity
-
-7: LuaEntity:
-  u8 compatibility_byte (always 1)
-  u16 len
-  u8[len] entity name
-  u32 len
-  u8[len] static data
-  s16 hp
-  s32 velocity.x * 10000
-  s32 velocity.y * 10000
-  s32 velocity.z * 10000
-  s32 yaw * 1000
-  if PROTOCOL_VERSION >= 37:
-    u8 version2 (=1)
-    s32 pitch * 1000
-    s32 roll * 1000
-
-Itemstring format
-------------------
-eg. 'default:dirt 5'
-eg. 'default:pick_wood 21323'
-eg. '"default:apple" 2'
-eg. 'default:apple'
-- The wear value in tools is 0...65535
-- There are also a number of older formats that you might stumble upon:
-eg. 'node "default:dirt" 5'
-eg. 'NodeItem default:dirt 5'
-eg. 'ToolItem WPick 21323'
-
-Inventory serialization format
--------------------------------
-- The inventory serialization format is line-based
-- The newline character used is "\n"
-- The end condition of a serialized inventory is always "EndInventory\n"
-- All the slots in a list must always be serialized.
-
-Example (format does not include "---"):
----
-List foo 4
-Item default:sapling
-Item default:sword_stone 1 10647
-Item default:dirt 99
-Empty
-EndInventoryList
-List bar 9
-Empty
-Empty
-Empty
-Empty
-Empty
-Empty
-Empty
-Empty
-Empty
-EndInventoryList
-EndInventory
----