From 7d61373b827b8ee86c8cb063472e8b04d1d2bbc8 Mon Sep 17 00:00:00 2001
From: Ryan Dick <ryanjdick3@gmail.com>
Date: Tue, 3 Oct 2023 11:20:12 -0400
Subject: [PATCH] Add LibcUtil class.

---
 .../backend/model_management/libc_util.py     | 74 +++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 invokeai/backend/model_management/libc_util.py

diff --git a/invokeai/backend/model_management/libc_util.py b/invokeai/backend/model_management/libc_util.py
new file mode 100644
index 0000000000..68074235fa
--- /dev/null
+++ b/invokeai/backend/model_management/libc_util.py
@@ -0,0 +1,74 @@
+import ctypes
+
+
+class Struct_mallinfo2(ctypes.Structure):
+    """A ctypes Structure that matches the libc mallinfo2 struct.
+
+    Docs:
+    - https://man7.org/linux/man-pages/man3/mallinfo.3.html
+    - https://www.gnu.org/software/libc/manual/html_node/Statistics-of-Malloc.html
+
+    struct mallinfo2 {
+        size_t arena;     /* Non-mmapped space allocated (bytes) */
+        size_t ordblks;   /* Number of free chunks */
+        size_t smblks;    /* Number of free fastbin blocks */
+        size_t hblks;     /* Number of mmapped regions */
+        size_t hblkhd;    /* Space allocated in mmapped regions (bytes) */
+        size_t usmblks;   /* See below */
+        size_t fsmblks;   /* Space in freed fastbin blocks (bytes) */
+        size_t uordblks;  /* Total allocated space (bytes) */
+        size_t fordblks;  /* Total free space (bytes) */
+        size_t keepcost;  /* Top-most, releasable space (bytes) */
+    };
+    """
+
+    _fields_ = [
+        ("arena", ctypes.c_size_t),
+        ("ordblks", ctypes.c_size_t),
+        ("smblks", ctypes.c_size_t),
+        ("hblks", ctypes.c_size_t),
+        ("hblkhd", ctypes.c_size_t),
+        ("usmblks", ctypes.c_size_t),
+        ("fsmblks", ctypes.c_size_t),
+        ("uordblks", ctypes.c_size_t),
+        ("fordblks", ctypes.c_size_t),
+        ("keepcost", ctypes.c_size_t),
+    ]
+
+    def __str__(self):
+        s = ""
+        s += f"{'arena': <10}= {(self.arena/2**30):15.5f}   # Non-mmapped space allocated (GB) (uordblks + fordblks)\n"
+        s += f"{'ordblks': <10}= {(self.ordblks): >15}   # Number of free chunks\n"
+        s += f"{'smblks': <10}= {(self.smblks): >15}   # Number of free fastbin blocks \n"
+        s += f"{'hblks': <10}= {(self.hblks): >15}   # Number of mmapped regions \n"
+        s += f"{'hblkhd': <10}= {(self.hblkhd/2**30):15.5f}   # Space allocated in mmapped regions (GB)\n"
+        s += f"{'usmblks': <10}= {(self.usmblks): >15}   # Unused\n"
+        s += f"{'fsmblks': <10}= {(self.fsmblks/2**30):15.5f}   # Space in freed fastbin blocks (GB)\n"
+        s += (
+            f"{'uordblks': <10}= {(self.uordblks/2**30):15.5f}   # Space used by in-use allocations (non-mmapped)"
+            " (GB)\n"
+        )
+        s += f"{'fordblks': <10}= {(self.fordblks/2**30):15.5f}   # Space in free blocks (non-mmapped) (GB)\n"
+        s += f"{'keepcost': <10}= {(self.keepcost/2**30):15.5f}   # Top-most, releasable space (GB)\n"
+
+
+class LibcUtil:
+    """A utility class for interacting with the C Standard Library (`libc`) via ctypes.
+
+    Note that this class will raise on __init__() if 'libc.so.6' can't be found. Take care to handle environments where
+    this shared library is not available.
+
+    TODO: Improve cross-OS copatibility of this class.
+    """
+
+    def __init__(self):
+        self._libc = ctypes.cdll.LoadLibrary("libc.so.6")
+
+    def mallinfo2(self) -> Struct_mallinfo2:
+        """Calls `libc` `mallinfo2`.
+
+        Docs: https://man7.org/linux/man-pages/man3/mallinfo.3.html
+        """
+        mallinfo2 = self._libc.mallinfo2
+        mallinfo2.restype = Struct_mallinfo2
+        return mallinfo2()