From 1caddd4f6edd3342f349c5cbf6b8185bca4d54b5 Mon Sep 17 00:00:00 2001
From: Elliott Sales de Andrade <quantum.analyst@gmail.com>
Date: Fri, 18 Sep 2026 02:41:03 -0400
Subject: [PATCH 1/3] Allow building against a system Zlib

Also, don't build vendored Zlib internally if not using vendored blosc,
as it isn't necessary.

And drop the extra licenses.

Signed-off-by: Elliott Sales de Andrade <quantum.analyst@gmail.com>
---
 meson.options             |  6 ++--
 pyproject.toml            |  2 --
 src/numcodecs/meson.build | 64 +++++++++++++++++++++------------------
 3 files changed, 38 insertions(+), 34 deletions(-)

diff --git a/meson.options b/meson.options
index 26a2414..f055af8 100644
--- a/meson.options
+++ b/meson.options
@@ -1,9 +1,11 @@
 option('system_blosc', type: 'feature', value: 'disabled',
        description: 'Use system-installed Blosc library')
-option('system_zstd', type: 'feature', value: 'disabled',
-       description: 'Use system-installed Zstandard library')
 option('system_lz4', type: 'feature', value: 'disabled',
        description: 'Use system-installed LZ4 library')
+option('system_zlib', type: 'feature', value: 'disabled',
+       description: 'Use system-installed Zlib library')
+option('system_zstd', type: 'feature', value: 'disabled',
+       description: 'Use system-installed Zstandard library')
 option('sse2', type: 'feature', value: 'auto',
        description: 'Enable SSE2 SIMD optimizations')
 option('avx2', type: 'feature', value: 'auto',
diff --git a/pyproject.toml b/pyproject.toml
index 185ecc3..192df28 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,8 +36,6 @@ maintainers = [
 license = "MIT"
 license-files = [
     "LICENSE.txt",
-    "c-blosc/LICENSE.txt",
-    "c-blosc/LICENSES/*",
 ]
 
 [project.urls]
diff --git a/src/numcodecs/meson.build b/src/numcodecs/meson.build
index eca2b2c..41a3a7a 100644
--- a/src/numcodecs/meson.build
+++ b/src/numcodecs/meson.build
@@ -123,39 +123,43 @@ if not lz4_dep.found()
   )
 endif
 
-# --- Vendored zlib (always vendored, used by blosc) ---
-zlib_sources = files(
-  '../../c-blosc/internal-complibs/zlib-1.3.1/adler32.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/compress.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/crc32.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/deflate.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/gzclose.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/gzlib.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/gzread.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/gzwrite.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/infback.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/inffast.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/inflate.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/inftrees.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/trees.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/uncompr.c',
-  '../../c-blosc/internal-complibs/zlib-1.3.1/zutil.c',
-)
-zlib_inc = include_directories('../../c-blosc/internal-complibs/zlib-1.3.1')
-
-zlib_lib = static_library('zlib_vendored', zlib_sources,
-  include_directories: zlib_inc,
-  c_args: c_args,
-)
-zlib_dep = declare_dependency(
-  link_with: zlib_lib,
-  include_directories: zlib_inc,
-)
-
 # --- Vendored blosc ---
 blosc_dep = dependency('blosc', required: get_option('system_blosc'))
 
 if not blosc_dep.found()
+  # --- Vendored zlib ---
+  zlib_dep = dependency('zlib', required: get_option('system_zlib'))
+
+  if not zlib_dep.found()
+    zlib_sources = files(
+      '../../c-blosc/internal-complibs/zlib-1.3.1/adler32.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/compress.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/crc32.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/deflate.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/gzclose.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/gzlib.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/gzread.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/gzwrite.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/infback.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/inffast.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/inflate.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/inftrees.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/trees.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/uncompr.c',
+      '../../c-blosc/internal-complibs/zlib-1.3.1/zutil.c',
+    )
+    zlib_inc = include_directories('../../c-blosc/internal-complibs/zlib-1.3.1')
+
+    zlib_lib = static_library('zlib_vendored', zlib_sources,
+      include_directories: zlib_inc,
+      c_args: c_args,
+    )
+    zlib_dep = declare_dependency(
+      link_with: zlib_lib,
+      include_directories: zlib_inc,
+    )
+  endif
+
   blosc_sources = files(
     '../../c-blosc/blosc/blosc.c',
     '../../c-blosc/blosc/blosclz.c',
@@ -207,7 +211,7 @@ endif
 # Extensions with C library dependencies
 py.extension_module('blosc',
   'blosc.pyx',
-  dependencies: [blosc_dep, lz4_dep, zlib_dep, zstd_dep],
+  dependencies: [blosc_dep],
   c_args: c_args,
   link_args: link_args,
   install: true,
-- 
2.54.0