From d6d1fd32fb90e9adafa8edc6b281c169b4a0689d Mon Sep 17 00:00:00 2001
From: Rokas Kupstys <19151258+rokups@users.noreply.github.com>
Date: Wed, 16 Jun 2021 12:13:47 +0300
Subject: [PATCH 1/3] Add Str::replace(find, repl) function.

---
 Str.h | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/Str.h b/Str.h
index 6d3fbee..93b83b3 100644
--- a/Str.h
+++ b/Str.h
@@ -161,6 +161,7 @@ class STR_API Str
     int                 append_from(int idx, const char* s, const char* s_end = NULL);		// If you know the string length or want to append from a certain point
     int                 appendf_from(int idx, const char* fmt, ...);
     int                 appendfv_from(int idx, const char* fmt, va_list args);
+    void                replace(const char* find, const char* repl);
 
     void                clear();
     void                reserve(int cap);
@@ -651,6 +652,49 @@ int     Str::appendf(const char* fmt, ...)
     return len;
 }
 
+void Str::replace(const char* find, const char* repl)
+{
+    STR_ASSERT(Owned == 1);
+    STR_ASSERT(find != NULL && *find);
+    STR_ASSERT(repl != NULL);
+    int find_len = (int)strlen(find);
+    int repl_len = (int)strlen(repl);
+    int repl_diff = repl_len - find_len;
+
+    // Estimate required length of new buffer if string size increases.
+    if (repl_diff > 0)
+    {
+        int need_capacity = length();
+        for (char* p = Data, *end = Data + length(); p != NULL && p < end;)
+        {
+            p = (char*)memmem(p, end - p, find, find_len);
+            if (p)
+            {
+                need_capacity += repl_diff;
+                p += find_len;
+            }
+        }
+        if (need_capacity > Capacity)
+        {
+            reserve(need_capacity);
+            STR_ASSERT(Capacity >= need_capacity);
+        }
+    }
+
+    // Replace data.
+    for (char* p = Data, *end = Data + length(); p != NULL && p < end;)
+    {
+        p = (char*)memmem(p, end - p, find, find_len);
+        if (p)
+        {
+            memmove(p + repl_len, p + find_len, end - p - find_len + 1);
+            memcpy(p, repl, repl_len);
+            p += repl_len;
+            end += repl_diff;
+        }
+    }
+}
+
 #endif // #define STR_IMPLEMENTATION
 
 //-------------------------------------------------------------------------

From 39c8e1b9f08159a7e24cda405d40c854bdc3f126 Mon Sep 17 00:00:00 2001
From: Rokas Kupstys <rokups@zoho.com>
Date: Fri, 18 Jun 2021 12:52:12 +0300
Subject: [PATCH 2/3] [SQUASH] Take ownership of non-owned string when
 replacing and fix allocating too small buffer when buffer resize is needed.

---
 Str.h | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/Str.h b/Str.h
index 93b83b3..aa96ec6 100644
--- a/Str.h
+++ b/Str.h
@@ -652,9 +652,8 @@ int     Str::appendf(const char* fmt, ...)
     return len;
 }
 
-void Str::replace(const char* find, const char* repl)
+void    Str::replace(const char* find, const char* repl)
 {
-    STR_ASSERT(Owned == 1);
     STR_ASSERT(find != NULL && *find);
     STR_ASSERT(repl != NULL);
     int find_len = (int)strlen(find);
@@ -662,9 +661,10 @@ void Str::replace(const char* find, const char* repl)
     int repl_diff = repl_len - find_len;
 
     // Estimate required length of new buffer if string size increases.
+    int need_capacity = Capacity;
     if (repl_diff > 0)
     {
-        int need_capacity = length();
+        need_capacity = length() + 1;
         for (char* p = Data, *end = Data + length(); p != NULL && p < end;)
         {
             p = (char*)memmem(p, end - p, find, find_len);
@@ -674,13 +674,14 @@ void Str::replace(const char* find, const char* repl)
                 p += find_len;
             }
         }
-        if (need_capacity > Capacity)
-        {
-            reserve(need_capacity);
-            STR_ASSERT(Capacity >= need_capacity);
-        }
     }
 
+    const char* not_owned_data = Owned ? NULL : Data;
+    if (!Owned || need_capacity > Capacity)
+        reserve(need_capacity);
+    if (not_owned_data != NULL)
+        set(not_owned_data);
+
     // Replace data.
     for (char* p = Data, *end = Data + length(); p != NULL && p < end;)
     {

From e7f8701757b9762f6b79e08313209ffa480a57bb Mon Sep 17 00:00:00 2001
From: Rokas Kupstys <rokups@zoho.com>
Date: Fri, 18 Jun 2021 13:13:25 +0300
Subject: [PATCH 3/3] [SQUASH] Attempt early out from replacement loop when
 possible.

---
 Str.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Str.h b/Str.h
index aa96ec6..3a2c7bb 100644
--- a/Str.h
+++ b/Str.h
@@ -662,8 +662,10 @@ void    Str::replace(const char* find, const char* repl)
 
     // Estimate required length of new buffer if string size increases.
     int need_capacity = Capacity;
+    int num_matches = INT_MAX;
     if (repl_diff > 0)
     {
+        num_matches = 0;
         need_capacity = length() + 1;
         for (char* p = Data, *end = Data + length(); p != NULL && p < end;)
         {
@@ -672,10 +674,14 @@ void    Str::replace(const char* find, const char* repl)
             {
                 need_capacity += repl_diff;
                 p += find_len;
+                num_matches++;
             }
         }
     }
 
+    if (num_matches == 0)
+        return;
+
     const char* not_owned_data = Owned ? NULL : Data;
     if (!Owned || need_capacity > Capacity)
         reserve(need_capacity);
@@ -683,7 +689,7 @@ void    Str::replace(const char* find, const char* repl)
         set(not_owned_data);
 
     // Replace data.
-    for (char* p = Data, *end = Data + length(); p != NULL && p < end;)
+    for (char* p = Data, *end = Data + length(); p != NULL && p < end && num_matches--;)
     {
         p = (char*)memmem(p, end - p, find, find_len);
         if (p)