docs: moved reference counting to memory management

Author: NickSdot

docs/source/_templates/redirect.html

@@ -0,0 +1,15 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <meta http-equiv="refresh" content="0; url={{ redirect_url }}">
+    <link rel="canonical" href="{{ redirect_url }}">
+    <title>Redirecting&hellip;</title>
+    <script>
+      window.location.replace({{ redirect_url | tojson }} + window.location.hash);
+    </script>
+  </head>
+  <body>
+    <p>This page has moved to <a href="{{ redirect_url }}">its new location</a>.</p>
+  </body>
+</html>

docs/source/conf.py

@@ -67,3 +67,17 @@
 )
 html_theme_options = asdict(theme_options)
 pygments_style = 'sphinx'
+
+
+redirects = {
+    'core/data-structures/reference-counting': '../memory-management/reference-counting.html',
+}
+
+
+def generate_redirects(_app):
+    for source, target in redirects.items():
+        yield source, {'redirect_url': target}, 'redirect.html'
+
+
+def setup(app):
+    app.connect('html-collect-pages', generate_redirects)

docs/source/core/data-structures/index.md

@@ -1,10 +1,9 @@
-# Data structures
+# Data Structures
 
 ```{toctree}
    :hidden:
 
 zval
-reference-counting
 zend_string
 zend_constant
 ```

docs/source/core/data-structures/zend_string.md

@@ -22,9 +22,9 @@ the strings length, along with some other fields. It looks as follows:
    };
 ```
 
-The `gc` field is used for {doc}`./reference-counting`. The `h` field contains a hash value, which is
-used for hash table lookups. The `len` field stores the length of the string in bytes, and the `val`
-field contains the actual string data.
+The `gc` field is used for {doc}`../memory-management/reference-counting`. The `h` field contains a hash value,
+which is used for hash table lookups. The `len` field stores the length of the string in bytes, and
+the `val` field contains the actual string data.
 
 You may wonder why the `val` field is declared as `char val[1]`. This is called the [struct
 hack](https://www.geeksforgeeks.org/struct-hack/) in C. It is used to create structs with a flexible size, namely by allowing the last element
@@ -145,7 +145,7 @@ strings.
 
    -  -  `zend_string_separate(s)`
       -  Duplicates the string if the reference count is greater than 1. See
-         {doc}`./reference-counting` for details.
+         {doc}`../memory-management/reference-counting` for details.
 
    -  -  `zend_string_realloc(s, l, p)`
 
@@ -167,9 +167,9 @@ Programs use some strings many times. For example, if your program declares a cl
 `MyClass`, it would be wasteful to allocate a new string `"MyClass"` every time it is referenced
 within your program. Instead, when repeated strings are expected, php-src uses a technique called
 string interning. Essentially, this is just a simple `HashTable` where existing interned strings are
-stored. When creating a new interned string, php-src first checks the interned string
-buffer. If it finds it there, it can return a pointer to the existing string. If it doesn't, it
-allocates a new string and adds it to the buffer.
+stored. When creating a new interned string, php-src first checks the interned string buffer. If it
+finds it there, it can return a pointer to the existing string. If it doesn't, it allocates a new
+string and adds it to the buffer.
 
 ```c
 

docs/source/core/data-structures/zval.md

@@ -64,9 +64,9 @@ member, but never both at the same time. However, it doesn't know which member i
 Remembering this is our job, and that's exactly what the `IS_*` constants are for.
 
 The top members of `zend_value` mostly mirror the `IS_*` constants, with the exception of
-`counted`. `counted` polymorphically refers to any [reference-counted](reference-counting.md) value,
-including strings, arrays, objects, resources and references. `null` and `bool` are missing from
-`zend_value` because their types are self-contained.
+`counted`. `counted` polymorphically refers to any [reference-counted](../memory-management/reference-counting.md)
+value, including strings, arrays, objects, resources and references. `null` and `bool` are missing
+from `zend_value` because their types are self-contained.
 
 The rest of the fields aren't important for now.
 
@@ -112,7 +112,8 @@ intimidating at first. We'll go over it step by step.
 `zval.u1` stores the variable type, the given `IS_*` constant, along with some other flags. It's
 definition looks a bit complicated. You can think of the entire field as a 4 byte integer, split
 into 3 parts. `v.type` stores the actual variable type, `v.type_flags` is used for some
-[reference-counting](reference-counting.md) flags, and `v.u.extra` is pretty much unused.
+[reference-counting](../memory-management/reference-counting.md) flags, and `v.u.extra` is pretty
+much unused.
 
 `zval.u2` defines some more storage for various contexts that is often unoccupied. It's there
 because the memory would otherwise be wasted due to padding, so we may as well make use of it. We'll

docs/source/core/memory-management/index.md

@@ -0,0 +1,10 @@
+# Memory Management
+
+```{toctree}
+---
+hidden: true
+---
+reference-counting
+```
+
+This section describes how php-src manages the lifetime of allocated data.

…re/data-structures/reference-counting.md …/memory-management/reference-counting.mddocs/source/core/data-structures/reference-counting.md renamed to docs/source/core/memory-management/reference-counting.md docs/source/core/data-structures/reference-counting.md renamed to docs/source/core/memory-management/reference-counting.md

@@ -1,4 +1,4 @@
-# Reference counting
+# Reference Counting
 
 In languages like C, when you need memory for storing data for an indefinite period of time or in a
 large amount, you call `malloc` and `free` to acquire and release blocks of memory of some size.

docs/source/index.md

@@ -13,6 +13,7 @@ introduction/ides/index
    :hidden:
 
 core/data-structures/index
+core/memory-management/index
 core/output-buffering
 ```