Gzip support for inflate

libz-rs-sys/src/lib.rs

@@ -11,7 +11,7 @@ use std::ffi::{c_char, c_int, c_long, c_uchar, c_uint, c_ulong, c_void};
 
 use zlib_rs::{
     deflate::{DeflateConfig, DeflateStream, Method, Strategy},
-    inflate::{InflateConfig, InflateStream},
+    inflate::{GzipHeader, InflateConfig, InflateStream},
     Flush, ReturnCode,
 };
 
@@ -199,9 +199,18 @@ pub unsafe extern "C" fn inflateSetDictionary(
     zlib_rs::inflate::set_dictionary(stream, dict) as _
 }
 
-// pub unsafe extern "C" fn inflateGetHeader(strm: z_streamp, head: gz_headerp) -> c_int {
-//     todo!("part of gzip support")
-// }
+// part of gzib
+pub unsafe extern "C" fn inflateGetHeader(strm: z_streamp, head: gz_headerp) -> c_int {
+    if let Some(stream) = InflateStream::from_stream_mut(strm) {
+        if let Some(header) = GzipHeader::from_header_mut(head) {
+            zlib_rs::inflate::get_header(stream, header) as i32
+        } else {
+            ReturnCode::StreamError as _
+        }
+    } else {
+        ReturnCode::StreamError as _
+    }
+}
 
 // undocumented but exposed function
 pub unsafe extern "C" fn inflateUndermine(strm: *mut z_stream, subvert: i32) -> c_int {

zlib-rs/src/c_api.rs

@@ -124,3 +124,36 @@ pub const Z_HUFFMAN_ONLY: c_int = 2;
 pub const Z_RLE: c_int = 3;
 pub const Z_FIXED: c_int = 4;
 pub const Z_DEFAULT_STRATEGY: c_int = 0;
+
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct gz_header {
+
+    /// true if contents is propably text
+    pub text: c_int,
+
+    /// modification time
+    pub time: z_size,
+    pub xflags: c_int,
+    pub os: c_int,
+
+    pub extra: *mut Bytef,
+    pub extra_len: uInt,
+    pub extra_max: uInt,
+
+    /// file name
+    pub name: *mut Bytef,
+    pub name_max: uInt,
+
+    /// comment
+    pub comment: *mut Bytef,
+    pub comment_max: uInt,
+
+    /// true for a header CRC16
+    pub hcrc: c_int,
+
+    /// true when done reading header
+    pub done: c_int,
+}
+
+pub type gz_headerp = *mut gz_header;