feat: new tiny decoder for ShortCode

src/main.cc

@@ -269,14 +269,16 @@ int main() {
 //        }
 //    }
 
-    auto br = BasicRanges::fetch();
-    for (auto &range : br) {
-        range = Common::range_reverse(range);
-    }
+    printf("%09lX\n", ShortCode::tiny_decode_demo(14323231));
+
+//    auto br = BasicRanges::fetch();
+//    for (auto &range : br) {
+//        range = Common::range_reverse(range);
+//    }
     /// 1017983: 0FFFFFFF
     /// 1017984: 10000000
     /// 1017985: 1000000C
-    int sum = 0;
+//    int sum = 0;
 //    printf("    ");
 //    for (uint32_t prefix = 0; prefix < 0x1000; ++prefix) {
 //        printf("%7td, ", std::lower_bound(br.begin(), br.end(), prefix << 20) - br.begin());
@@ -285,17 +287,17 @@ int main() {
 //        }
 //    }
 
-    for (int head = 0; head < 16; ++head) {
-        auto &a = AllCases::fetch()[head];
-        printf("\n/// --------------------------------- 0x%X ---------------------------------\n    ", head);
-        for (uint32_t prefix = 0; prefix < 0x1000; ++prefix) {
-            printf("%7td, ", std::lower_bound(a.begin(), a.end(), prefix << 20) - a.begin());
-            if (sum++ % 8 == 7 and prefix != 0xFFF) {
-                printf("\n    ");
-            }
-        }
-    }
-    printf("\n");
+//    for (int head = 0; head < 16; ++head) {
+//        auto &a = AllCases::fetch()[head];
+//        printf("\n/// --------------------------------- 0x%X ---------------------------------\n    ", head);
+//        for (uint32_t prefix = 0; prefix < 0x1000; ++prefix) {
+//            printf("%7td, ", std::lower_bound(a.begin(), a.end(), prefix << 20) - a.begin());
+//            if (sum++ % 8 == 7 and prefix != 0xFFF) {
+//                printf("\n    ");
+//            }
+//        }
+//    }
+//    printf("\n");
 
 //    printf("%09lX\n", ShortCode::fast_decode(14323231));
 //    std::cout << ShortCode::fast_encode(0x6EC0F8800) << std::endl;

src/short_code/data_loader.cc

@@ -66,3 +66,49 @@ uint32_t ShortCode::fast_encode(uint64_t common_code) {
     auto offset = std::lower_bound(ranges.begin(), ranges.end(), (uint32_t)common_code) - ranges.begin();
     return ALL_CASES_OFFSET[head] + offset; // release short code
 }
+
+#include "basic_ranges_offset.h"
+#include "range_prefix_offset.h"
+
+#include <iostream>
+#include "common.h"
+
+uint64_t ShortCode::tiny_decode_demo(uint32_t short_code) {
+    /// match head index
+    auto offset = std::upper_bound( // binary search
+        ALL_CASES_OFFSET, ALL_CASES_OFFSET + 16, short_code
+    ) - 1;
+    uint64_t head = offset - ALL_CASES_OFFSET; // head index
+    short_code -= *offset;
+
+    /// match range prefix
+    offset = std::upper_bound( // binary search
+        RANGE_PREFIX_OFFSET_[head], RANGE_PREFIX_OFFSET_[head] + 4096, short_code
+    ) - 1;
+    uint32_t prefix = offset - RANGE_PREFIX_OFFSET_[head]; // range prefix
+    short_code -= *offset;
+
+    uint32_t start_point = BASIC_RANGES_OFFSET_[prefix];
+
+    printf("prefix: %X\n", prefix);
+    printf("start at %d\n", start_point);
+    printf("next %d valid case\n", short_code);
+
+    uint32_t range;
+
+    for (auto index = start_point; index < BasicRanges::fetch().size(); ++index) { // traverse basic ranges
+        range = BasicRanges::fetch()[index];
+        if (Common::check_case(head, range)) { // search for valid cases
+
+            if (!short_code--) { // short code approximate
+                break; // found target range
+            }
+
+        }
+    }
+
+    printf("range -> %08X\n", Common::range_reverse(range));
+
+    return (uint64_t)head << 32 | Common::range_reverse(range);
+
+}

src/short_code/offset/all_cases_offset.h

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <cstdint>
+
+const uint32_t ALL_CASES_OFFSET_[16] = {
+           0,  2942906,  5203298,  8146204,
+     8146204, 10468254, 12345199, 14667249,
+    14667249, 16989299, 18866244, 21188294,
+    21188294, 24131200, 26391592, 29334498,
+};

src/short_code/offset/basic_ranges_offset.h

@@ -2,7 +2,7 @@
 
 #include <cstdint>
 
-const uint32_t BASIC_RANGES_OFFSET[4096] = {
+const uint32_t BASIC_RANGES_OFFSET_[4096] = {
           0,   18272,   24960,   31648,   49920,   56608,   59056,   61504,
       68192,   74880,   77328,   79776,   86464,  104736,  111424,  118112,
      136384,  143072,  145520,  147968,  154656,  157104,  158000,  158896,

src/short_code/offset/range_prefix_offset.h

@@ -2,7 +2,7 @@
 
 #include <cstdint>
 
-const uint32_t RANGE_PREFIX_OFFSET[16][4096] = {
+const uint32_t RANGE_PREFIX_OFFSET_[16][4096] = {
 /// --------------------------------- 0x0 ---------------------------------
           0,    9527,   12991,   16067,   25594,   29058,   30527,   31657,
       35121,   38525,   39766,   41041,   44445,   53972,   57436,   60512,

src/short_code/short_code.h

@@ -37,8 +37,8 @@ public:
     static uint64_t fast_decode(uint32_t short_code);
     static uint32_t fast_encode(uint64_t common_code);
 
-    static uint64_t tidy_decode_demo(uint32_t short_code);
-    static uint32_t tidy_encode_demo(uint64_t common_code);
+    static uint64_t tiny_decode_demo(uint32_t short_code);
+    static uint32_t tiny_encode_demo(uint64_t common_code);
 
 private:
     uint32_t code;