Recreate base64 project

base64/base64.c

@@ -0,0 +1,140 @@
+// vim:fileencoding=utf-8:foldmethod=marker
+
+#include "base64.h"
+#include "../wapp/wapp.h"
+#include <math.h>
+
+internal Str8RO alphabet = wapp_str8_lit_ro("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/");
+
+internal c8 char_at(u8 index);
+internal u8 char_index(c8 c);
+internal u64 calc_encode_length(Str8RO *input);
+internal u64 calc_decode_length(Str8RO *input);
+
+Str8 *encode(Allocator *allocator, Str8RO *input) {
+  if (input->size == 0) {
+    return NULL;
+  }
+
+  u64 n_out = calc_encode_length(input);
+  Str8 *out = wapp_str8_alloc_and_fill_buf(allocator, n_out);
+  if (!out) return NULL;
+
+  u8 buf[3] = {0};
+  u8 count  = 0;
+  u64 iout  = 0;
+
+
+  for (u64 i = 0; i < input->size; ++i) {
+    buf[count] = wapp_str8_get(input, i);
+    count += 1;
+    if (count == 3) {
+      wapp_str8_set(out, iout, char_at(buf[0] >> 2));
+      wapp_str8_set(out, iout + 1, char_at(((buf[0] & 0x03) << 4) + (buf[1] >> 4)));
+      wapp_str8_set(out, iout + 2, char_at(((buf[1] & 0x0f) << 2) + (buf[2] >> 6)));
+      wapp_str8_set(out, iout + 3, char_at(buf[2] & 0x3f));
+
+      iout += 4;
+      count = 0;
+    }
+  }
+
+  if (count == 1)  {
+    wapp_str8_set(out, iout, char_at(buf[0] >> 2));
+    wapp_str8_set(out, iout + 1, char_at((buf[0] & 0x03) << 4));
+    wapp_str8_set(out, iout + 2, '=');
+    wapp_str8_set(out, iout + 3, '=');
+  }
+
+  if (count == 2) {
+    wapp_str8_set(out, iout, char_at(buf[0] >> 2));
+    wapp_str8_set(out, iout + 1, char_at(((buf[0] & 0x03) << 4) + (buf[1] >> 4)));
+    wapp_str8_set(out, iout + 2, char_at((buf[1] & 0x0f) << 2));
+    wapp_str8_set(out, iout + 3, '=');
+
+    iout += 4;
+  }
+
+  return out;
+}
+
+Str8 *decode(Allocator *allocator, Str8RO *input) {
+  if (input->size == 0) {
+    return NULL;
+  }
+
+  u64 n_out = calc_decode_length(input);
+  Str8 *out = wapp_str8_alloc_and_fill_buf(allocator, n_out);
+  if (!out) return NULL;
+
+  u8 buf[4] = {0};
+  u8 count  = 0;
+  u64 iout  = 0;
+
+  for (u64 i = 0; i < input->size; ++i) {
+    buf[count] = char_index(wapp_str8_get(input, i));
+    count += 1;
+    if (count == 4) {
+      wapp_str8_set(out, iout, (buf[0] << 2) + (buf[1] >> 4));
+      if (buf[2] != 64) {
+        wapp_str8_set(out, iout + 1, (buf[1] << 4) + (buf[2] >> 2));
+      }
+      if (buf[3] != 64) {
+        wapp_str8_set(out, iout + 2, (buf[2] << 6) + buf[3]);
+      }
+
+      iout += 3;
+      count = 0;
+    }
+  }
+
+  return out;
+}
+
+internal c8 char_at(u8 index) {
+  return wapp_str8_get(&alphabet, index);
+}
+
+internal u8 char_index(c8 c) {
+  if (c == '=') {
+      return 64;
+  }
+
+  u8 index = 0;
+  for (u8 i = 0; i < 63; ++i) {
+    if (char_at(i) == c) {
+        break;
+    }
+    index += 1;
+  }
+
+  return index;
+}
+
+internal u64 calc_encode_length(Str8RO *input) {
+  if (input->size < 3) {
+    return 4;
+  }
+
+  u64 n_groups = (u64)(ceilf((f32)input->size / 3.0f));
+
+  return n_groups * 4;
+}
+
+internal u64 calc_decode_length(Str8RO *input) {
+  if (input->size < 4) {
+    return 3;
+  }
+
+  u64 n_groups = (u64)(floorf((f32)input->size / 4.0f));
+
+  u64 groups = n_groups * 3;
+
+  for (u64 i = input->size; i > 0; --i) {
+    if (wapp_str8_get(input, i) == '=') {
+      groups -= 1;
+    }
+  }
+
+  return groups;
+}

base64/base64.h

@@ -0,0 +1,11 @@
+// vim:fileencoding=utf-8:foldmethod=marker
+
+#ifndef BASE64_H
+#define BASE64_H
+
+#include "../wapp/wapp.h"
+
+Str8 *encode(Allocator *allocator, Str8RO *input);
+Str8 *decode(Allocator *allocator, Str8RO *input);
+
+#endif // !BASE64_H

base64/build

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+script_dir="$(dirname $0)"
+
+clang $script_dir/*.c $script_dir/../wapp/wapp.c -lm -o b64

base64/main.c

@@ -0,0 +1,23 @@
+// vim:fileencoding=utf-8:foldmethod=marker
+
+#include "base64.h"
+#include "../wapp/wapp.h"
+#include <stdio.h>
+
+int main(void) {
+  Allocator allocator = wapp_mem_arena_allocator_init(MB(10));
+
+  Str8RO text  = wapp_str8_lit_ro("Testing some more stuff");
+  Str8RO etext = wapp_str8_lit_ro("VGVzdGluZyBzb21lIG1vcmUgc3R1ZmY=");
+
+  Str8 *encoded_text = encode(&allocator, &text);
+  Str8 *decoded_text = decode(&allocator, &etext);
+  wapp_runtime_assert(encoded_text != NULL && decoded_text != NULL, "Failed to allocate strings");
+
+  printf("Encoded text: " WAPP_STR8_SPEC "\n", wapp_str8_varg(*encoded_text));
+  printf("Decoded text: " WAPP_STR8_SPEC "\n", wapp_str8_varg(*decoded_text));
+
+  wapp_mem_arena_allocator_destroy(&allocator);
+
+  return 0;
+}