From 872321105c6ada9266a7f070fae84082f6cf2519 Mon Sep 17 00:00:00 2001
From: yangwentong <425822674@qq.com>
Date: Fri, 14 Oct 2022 21:07:23 +0800
Subject: [PATCH] =?UTF-8?q?MaxSubmatch=E8=B0=83=E7=94=A8Rust=E5=AE=9E?=
 =?UTF-8?q?=E7=8E=B0?=
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---
 re2/re2.cc                | 17 +----------------
 regex-capi/include/rure.h |  1 +
 regex-capi/src/rure.rs    | 26 ++++++++++++++++++++++++++
 3 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/re2/re2.cc b/re2/re2.cc
index ca9775e..91d9880 100644
--- a/re2/re2.cc
+++ b/re2/re2.cc
@@ -1023,22 +1023,7 @@ namespace re2
   // E.g. if rewrite == "foo \\2,\\1", returns 2.
   int RE2::MaxSubmatch(const StringPiece &rewrite)
   {
-    int max = 0;
-    for (const char *s = rewrite.data(), *end = s + rewrite.size();
-         s < end; s++)
-    {
-      if (*s == '\\')
-      {
-        s++;
-        int c = (s < end) ? *s : -1;
-        if (isdigit(c))
-        {
-          int n = (c - '0');
-          if (n > max)
-            max = n;
-        }
-      }
-    }
+    int max = rure_max_submatch(rewrite.data());
     return max;
   }
 
diff --git a/regex-capi/include/rure.h b/regex-capi/include/rure.h
index 1817e25..6719486 100644
--- a/regex-capi/include/rure.h
+++ b/regex-capi/include/rure.h
@@ -610,6 +610,7 @@ const char *rure_replace_all(rure *re, const uint8_t *haystack, size_t len_h,
 
 rure *rure_new(const uint8_t *pattern, size_t length);
 bool rure_consume(rure *re, const uint8_t *haystack, size_t length, rure_match *match);
+int rure_max_submatch(const char *rewrite);
 
 #ifdef __cplusplus
 }
diff --git a/regex-capi/src/rure.rs b/regex-capi/src/rure.rs
index 17e3552..b88ffc4 100644
--- a/regex-capi/src/rure.rs
+++ b/regex-capi/src/rure.rs
@@ -721,3 +721,29 @@ ffi_fn! {
     }
 
 }
+
+ffi_fn! {
+    fn rure_max_submatch(rewrite: *const c_char) -> i32 {
+        let mut max: i32 = 0;
+        let mut flag = 0;
+        let zero_number = '0' as i32;
+        let len = unsafe { CStr::from_ptr(rewrite).to_bytes().len() };
+        let pat = rewrite as *const u8;
+        let text = unsafe { slice::from_raw_parts(pat, len) };
+        let rewrite = std::str::from_utf8(text).unwrap();
+        for s in rewrite.chars() {
+            if s == '\\' {
+                flag = 1;
+                continue;
+            }
+            if s.is_ascii_digit() && flag == 1 {
+                let max_ = s as i32 - zero_number;
+                if max_ > max {
+                    max = max_;
+                }
+                flag = 0;
+            }
+        }
+        max
+    }
+}
-- 
Gitee