Move String8 path functions to androidfw and aapt

Test: m checkbuild
Bug: 295394788
Change-Id: I9488bc5632cbd47c83f6b5f2df4c87eb324a1e8e

1 files changed, 135 insertions, 0 deletions

diff --git a/libs/androidfw/PathUtils.cpp b/libs/androidfw/PathUtils.cpp
new file mode 100644
index 000000000000..df7a9f06781b
--- /dev/null
+++ b/libs/androidfw/PathUtils.cpp
@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <androidfw/PathUtils.h>
+
+#include <utils/Compat.h>
+
+namespace android {
+
+String8 getPathLeaf(const String8& str) {
+    const char* cp;
+    const char*const buf = str.c_str();
+
+    cp = strrchr(buf, OS_PATH_SEPARATOR);
+    if (cp == nullptr)
+        return str;
+    else
+        return String8(cp+1);
+}
+
+String8 getPathDir(const String8& str8) {
+    const char* cp;
+    const char*const str = str8.c_str();
+
+    cp = strrchr(str, OS_PATH_SEPARATOR);
+    if (cp == nullptr)
+        return String8();
+    else
+        return String8(str, cp - str);
+}
+
+static char* findExtension(const String8& str8) {
+    const char* lastSlash;
+    const char* lastDot;
+    const char* const str = str8.c_str();
+
+    // only look at the filename
+    lastSlash = strrchr(str, OS_PATH_SEPARATOR);
+    if (lastSlash == nullptr)
+        lastSlash = str;
+    else
+        lastSlash++;
+
+    // find the last dot
+    lastDot = strrchr(lastSlash, '.');
+    if (lastDot == nullptr)
+        return nullptr;
+
+    // looks good, ship it
+    return const_cast<char*>(lastDot);
+}
+
+String8 getPathExtension(const String8& str) {
+    char* ext;
+
+    ext = findExtension(str);
+    if (ext != nullptr)
+        return String8(ext);
+    else
+        return String8();
+}
+
+String8 getBasePath(const String8& str8) {
+    char* ext;
+    const char* const str = str8.c_str();
+
+    ext = findExtension(str8);
+    if (ext == nullptr)
+        return str8;
+    else
+        return String8(str, ext - str);
+}
+
+static void setPathName(String8& s, const char* name) {
+    size_t len = strlen(name);
+    char* buf = s.lockBuffer(len);
+
+    memcpy(buf, name, len);
+
+    // remove trailing path separator, if present
+    if (len > 0 && buf[len - 1] == OS_PATH_SEPARATOR) len--;
+    buf[len] = '\0';
+
+    s.unlockBuffer(len);
+}
+
+String8& appendPath(String8& str, const char* name) {
+    // TODO: The test below will fail for Win32 paths. Fix later or ignore.
+    if (name[0] != OS_PATH_SEPARATOR) {
+        if (*name == '\0') {
+            // nothing to do
+            return str;
+        }
+
+        size_t len = str.length();
+        if (len == 0) {
+            // no existing filename, just use the new one
+            setPathName(str, name);
+            return str;
+        }
+
+        // make room for oldPath + '/' + newPath
+        int newlen = strlen(name);
+
+        char* buf = str.lockBuffer(len+1+newlen);
+
+        // insert a '/' if needed
+        if (buf[len-1] != OS_PATH_SEPARATOR)
+            buf[len++] = OS_PATH_SEPARATOR;
+
+        memcpy(buf+len, name, newlen+1);
+        len += newlen;
+
+        str.unlockBuffer(len);
+        return str;
+    } else {
+        setPathName(str, name);
+        return str;
+    }
+}
+
+} // namespace android