Gzip: compatibility with recent zlib-ng 2.2.x versions.

It now uses 5/4 times more memory for the pending buffer.

Further, a single allocation is now used, which takes additional 56 bytes
for deflate_allocs in 64-bit mode aligned to 16, to store sub-allocation
pointers, and the total allocation size now padded up to 128 bytes, which
takes theoretically 200 additional bytes in total.  This fits though into
"4 * (64 + sizeof(void*))" additional space for ZALLOC used in zlib-ng
2.1.x versions.  The comment was updated to reflect this.
This commit is contained in:
Sergey Kandaurov 2024-12-23 17:57:45 +04:00
parent 16f4b1934f
commit 09cda9195c

View File

@ -516,8 +516,10 @@ ngx_http_gzip_filter_memory(ngx_http_request_t *r, ngx_http_gzip_ctx_t *ctx)
/*
* Another zlib variant, https://github.com/zlib-ng/zlib-ng.
* It used to force window bits to 13 for fast compression level,
* uses (64 + sizeof(void*)) additional space on all allocations
* for alignment, 16-byte padding in one of window-sized buffers,
* used (64 + sizeof(void*)) additional space on all allocations
* for alignment and 16-byte padding in one of window-sized buffers,
* uses a single allocation with up to 200 bytes for alignment and
* internal pointers, 5/4 times more memory for the pending buffer,
* and 128K hash.
*/
@ -526,7 +528,7 @@ ngx_http_gzip_filter_memory(ngx_http_request_t *r, ngx_http_gzip_ctx_t *ctx)
}
ctx->allocated = 8192 + 16 + (1 << (wbits + 2))
+ 131072 + (1 << (memlevel + 8))
+ 131072 + (5 << (memlevel + 6))
+ 4 * (64 + sizeof(void*));
ctx->zlib_ng = 1;
}