Use custom class instead of std::map

native/jni/magiskboot/compress.cpp

@@ -607,8 +607,8 @@ void decompress(char *infile, const char *outfile) {
 }
 
 void compress(const char *method, const char *infile, const char *outfile) {
-    auto it = name2fmt.find(method);
-    if (it == name2fmt.end())
+    format_t fmt = name2fmt[method];
+    if (fmt == UNKNOWN)
         LOGE("Unknown compression method: [%s]\n", method);
 
     bool in_std = infile == "-"sv;
@@ -624,7 +624,7 @@ void compress(const char *method, const char *infile, const char *outfile) {
             /* If user does not provide outfile and infile is not
              * STDIN, output to <infile>.[ext] */
             string tmp(infile);
-            tmp += fmt2ext[it->second];
+            tmp += fmt2ext[fmt];
             out_fp = xfopen(tmp.data(), "we");
             fprintf(stderr, "Compressing to [%s]\n", tmp.data());
             rm_in = true;
@@ -633,7 +633,7 @@ void compress(const char *method, const char *infile, const char *outfile) {
         out_fp = outfile == "-"sv ? stdout : xfopen(outfile, "we");
     }
 
-    auto strm = get_encoder(it->second, make_unique<fp_stream>(out_fp));
+    auto strm = get_encoder(fmt, make_unique<fp_stream>(out_fp));
 
     char buf[4096];
     size_t len;

native/jni/magiskboot/format.cpp

@@ -1,26 +1,9 @@
-#include <string.h>
-
 #include "format.hpp"
 
-std::map<std::string_view, format_t> name2fmt;
+Name2Fmt name2fmt;
 Fmt2Name fmt2name;
 Fmt2Ext fmt2ext;
 
-class FormatInit {
-public:
-    FormatInit() {
-        name2fmt["gzip"] = GZIP;
-        name2fmt["xz"] = XZ;
-        name2fmt["lzma"] = LZMA;
-        name2fmt["bzip2"] = BZIP2;
-        name2fmt["lz4"] = LZ4;
-        name2fmt["lz4_legacy"] = LZ4_LEGACY;
-        name2fmt["lz4_lg"] = LZ4_LG;
-    }
-};
-
-static FormatInit init;
-
 #define CHECKED_MATCH(s) (len >= (sizeof(s) - 1) && BUFFER_MATCH(buf, s))
 
 format_t check_fmt(const void *buf, size_t len) {
@@ -103,3 +86,17 @@ const char *Fmt2Ext::operator[](format_t fmt) {
             return "";
     }
 }
+
+#define CHECK(s, f) else if (name == s) return f;
+
+format_t Name2Fmt::operator[](std::string_view name) {
+    if (0) {}
+    CHECK("gzip", GZIP)
+    CHECK("xz", XZ)
+    CHECK("lzma", LZMA)
+    CHECK("bzip2", BZIP2)
+    CHECK("lz4", LZ4)
+    CHECK("lz4_legacy", LZ4_LEGACY)
+    CHECK("lz4_lg", LZ4_LG)
+    else return UNKNOWN;
+}

native/jni/magiskboot/format.hpp

@@ -1,6 +1,5 @@
 #pragma once
 
-#include <map>
 #include <string_view>
 
 typedef enum {
@@ -69,8 +68,13 @@ public:
     const char *operator[](format_t fmt);
 };
 
+class Name2Fmt {
+public:
+    format_t operator[](std::string_view name);
+};
+
 format_t check_fmt(const void *buf, size_t len);
 
-extern std::map<std::string_view, format_t> name2fmt;
+extern Name2Fmt name2fmt;
 extern Fmt2Name fmt2name;
 extern Fmt2Ext fmt2ext;

native/jni/magiskboot/main.cpp

@@ -12,6 +12,12 @@
 
 using namespace std;
 
+static void print_methods() {
+    for (int fmt = GZIP; fmt < LZOP; ++fmt) {
+        fprintf(stderr, "%s ", fmt2name[(format_t) fmt]);
+    }
+}
+
 static void usage(char *arg0) {
     fprintf(stderr,
 R"EOF(MagiskBoot - Boot Image Modification Tool
@@ -96,8 +102,7 @@ Supported actions:
     <infile>/[outfile] can be '-' to be STDIN/STDOUT
     Supported methods: )EOF", arg0);
 
-    for (auto &it : name2fmt)
-        fprintf(stderr, "%s ", it.first.data());
+    print_methods();
 
     fprintf(stderr, R"EOF(
 
@@ -106,8 +111,7 @@ Supported actions:
     <infile>/[outfile] can be '-' to be STDIN/STDOUT
     Supported methods: )EOF");
 
-    for (auto &it : name2fmt)
-        fprintf(stderr, "%s ", it.first.data());
+    print_methods();
 
     fprintf(stderr, "\n\n");
     exit(1);