feat: tiny codec between short code and common code

src/main.cc

@@ -97,13 +97,16 @@ int main() {
 //    std::cout << ShortCode::check_mode() << std::endl;
 
 
-    auto s = ShortCode(14323231);
-//    auto s = ShortCode(14323231, ShortCode::NORMAL);
-//    auto s = ShortCode(14323231, ShortCode::FAST);
-    std::cout << s.unwrap() << std::endl;
-    std::cout << s.to_string() << std::endl;
-    std::cout << ShortCode("EP4HZ", ShortCode::NORMAL).unwrap() << std::endl;
-    std::cout << ShortCode("eP4hZ", ShortCode::FAST).to_string() << std::endl;
+//    auto s = ShortCode(14323231);
+////    auto s = ShortCode(14323231, ShortCode::NORMAL);
+////    auto s = ShortCode(14323231, ShortCode::FAST);
+//    std::cout << s.unwrap() << std::endl;
+//    std::cout << s.to_string() << std::endl;
+//    std::cout << ShortCode("EP4HZ", ShortCode::NORMAL).unwrap() << std::endl;
+//    std::cout << ShortCode("eP4hZ", ShortCode::FAST).to_string() << std::endl;
+
+    std::cout << ShortCode::tiny_encode(0x6EC0F8800) << std::endl;
+    printf("%09lX\n", ShortCode::tiny_decode(14323231));
 
     return 0;
 }

src/short_code/CMakeLists.txt

@@ -1,4 +1,4 @@
 cmake_minimum_required(VERSION 3.0)
 
-add_library(short_code data_loader.cc short_code.cc)
-target_link_libraries(short_code all_cases)
+add_library(short_code convert.cc short_code.cc data_loader.cc)
+target_link_libraries(short_code common all_cases)

src/short_code/convert.cc

@@ -0,0 +1,50 @@
+#include "common.h"
+#include "short_code.h"
+#include "basic_ranges.h"
+#include "short_code_mark.h"
+
+uint32_t ShortCode::tiny_encode(uint64_t common_code) { // common_code --low-memory--> short_code
+    uint32_t offset = 0;
+    uint32_t head = common_code >> 32; // common code head
+    uint32_t prefix = (common_code >> 24) & 0xFF; // common code range prefix
+    auto target = Common::range_reverse((uint32_t)common_code); // target range
+
+    for (int index = 0; index < BASIC_RANGES_INDEX[prefix]; ++index) { // traverse basic ranges
+        uint32_t range = (*BasicRanges::fetch())[index + BASIC_RANGES_OFFSET[prefix]];
+        if (range == target) {
+            break; // found target range
+        }
+        if (Common::check_case(head, range)) { // search for valid cases
+            ++offset; // record sub offset
+        }
+    }
+    return ALL_CASES_OFFSET[head] + RANGE_PREFIX_OFFSET[head][prefix] + offset;
+}
+
+uint64_t ShortCode::tiny_decode(uint32_t short_code) { // short_code --low-memory--> common_code
+    uint32_t head = 0, prefix = 0;
+    for (; head < 16; ++head) {
+        if (short_code < ALL_CASES_INDEX[head]) { // match head
+            break;
+        }
+        short_code -= ALL_CASES_INDEX[head]; // short code approximate
+    }
+    for (; prefix < 256; ++prefix) {
+        if (short_code < RANGE_PREFIX_INDEX[head][prefix]) { // match range prefix
+            break;
+        }
+        short_code -= RANGE_PREFIX_INDEX[head][prefix]; // short code approximate
+    }
+
+    uint32_t range;
+    for (int index = 0; index < BASIC_RANGES_INDEX[prefix]; ++index) { // traverse basic ranges
+        range = (*BasicRanges::fetch())[index + BASIC_RANGES_OFFSET[prefix]];
+        if (Common::check_case(head, range)) { // search for valid cases
+            if (short_code == 0) {
+                break; // found target range
+            }
+            --short_code; // short code approximate
+        }
+    }
+    return (uint64_t)head << 32 | Common::range_reverse(range); // release common code
+}

src/short_code/short_code.h

@@ -26,6 +26,9 @@ public:
         speed_up(mode);
     }
 
+    static uint64_t tiny_decode(uint32_t short_code);
+    static uint32_t tiny_encode(uint64_t common_code);
+
 private:
     uint32_t code;
     static std::mutex map_building;
@@ -36,4 +39,7 @@ private:
     static std::unordered_map<uint64_t, uint32_t> all_cases_dict; // common_code -> short_code
 
     static void build_mappings();
+
+//    static uint64_t tiny_decode(uint32_t short_code);
+//    static uint32_t tiny_encode(uint64_t common_code);
 };

src/short_code/short_code_chars.h

@@ -8,15 +8,11 @@ const char SHORT_CODE_TABLE[32] = {
     'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
 };
 
+/// `1`(49) ~ `Z`(90)
 const char SHORT_CODE_TABLE_REV[42] = {
-//  00  01  02  03  04  05  06  07  08
-     0,  1,  2,  3,  4,  5,  6,  7,  8,
-//  09  10  11  12  13  14  15
-    -1, -1, -1, -1, -1, -1, -1,
-//  16  17  18  19  20  21  22  23  24  25
-     9, 10, 11, 12, 13, 14, 15, 16, -1, 17,
-//  26  27  28  29  30  31  32  33  34  35
-    18, -1, 19, 20, -1, 21, 22, 23, 24, 25,
-//  36  37  38  39  40  41
-    26, 27, 28, 29, 30, 31,
+     0,  1,  2,  3,  4,  5,  6,  7,  8, // `1`(49) ~ `9`(57)
+    -1, -1, -1, -1, -1, -1, -1, // `:`(58) ~ `@`(64)
+     9, 10, 11, 12, 13, 14, 15, 16, -1, 17, // `A`(65) ~ `J`(74)
+    18, -1, 19, 20, -1, 21, 22, 23, 24, 25, // `K`(75) ~ `T`(84)
+    26, 27, 28, 29, 30, 31, // `U`(85) ~ `Z`(90)
 };