feat: added randomly generated URLs

.editorconfig

@@ -0,0 +1,5 @@
+root = true
+
+[*.{c,cpp,h}]
+indent_style = space
+indent_size = 2

Makefile

@@ -31,7 +31,7 @@ prod: cmake-release
 
 .PHONY: run
 run: build
-	@ LANDER_API_KEY=test ./build/Debug/lander
+	@ LANDER_BASE_URL=http://localhost:18080/ LANDER_API_KEY=test ./build/Debug/lander
 
 .PHONY: clean
 clean:

landerctl

@@ -6,10 +6,9 @@ URL=http://localhost:18080
 if [ "$1" = add ]; then
     curl \
         -XPOST \
-        -d "$3" \
+        -d "$2" \
         -H "X-Api-Key: $API_KEY" \
-        "$URL/$2"
-    echo "$URL/$2"
+        "$URL/$3"
 
 elif [ "$1" = get ]; then
     curl -is "$URL/$2" | grep -Po '(?<=location: ).*'

src/main.cpp

@@ -4,15 +4,23 @@ extern "C" {
 #include "ternarytrie.h"
 }
 
-int main() {
-  // Read in API key
-  char *api_key = getenv("LANDER_API_KEY");
-
-  if (api_key == NULL) {
-    printf("No API key provided.");
-    return 1;
+#define ENV(var, env_var)                                                      \
+  const char *var = getenv(env_var);                                           \
+  if (var == NULL) {                                                           \
+    printf("Missing environment variable %s.\n", env_var);                     \
+    return 1;                                                                  \
   }
 
+#define AUTH()                                                                 \
+  std::string provided_api_key = req.get_header_value("X-Api-Key");            \
+  if (strcmp(api_key, provided_api_key.c_str()) != 0) {                        \
+    return crow::response(crow::status::UNAUTHORIZED);                         \
+  }
+
+int main() {
+  ENV(api_key, "LANDER_API_KEY");
+  ENV(base_url, "LANDER_BASE_URL");
+
   TernaryTrie *trie = ternarytrie_init();
 
   std::string file_path = "lander.data";
@@ -20,24 +28,8 @@ int main() {
 
   crow::SimpleApp app;
 
-  CROW_ROUTE(app, "/<string>")
-      .methods(crow::HTTPMethod::Post)(
-          [api_key, trie](const crow::request &req, std::string s) {
-            // Authenticate request
-            std::string provided_api_key = req.get_header_value("X-Api-Key");
+  app.loglevel(crow::LogLevel::Warning);
 
-            if (strcmp(api_key, provided_api_key.c_str()) != 0) {
-              return crow::response(crow::status::UNAUTHORIZED);
-            }
-
-            bool res = ternarytrie_add(trie, s.c_str(), req.body.c_str());
-
-            if (!res) {
-              return crow::response(crow::status::CONFLICT);
-            }
-
-            return crow::response(crow::status::NO_CONTENT);
-          });
   CROW_ROUTE(app, "/<string>")
       .methods(crow::HTTPMethod::Get)(
           [trie](crow::response &res, std::string s) {
@@ -51,6 +43,31 @@ int main() {
 
             res.end();
           });
+  CROW_ROUTE(app, "/").methods(crow::HTTPMethod::Post)(
+      [api_key, base_url, trie](const crow::request req) {
+        AUTH();
+
+        char *key = ternarytrie_add_random(trie, req.body.c_str());
+
+        if (key == NULL) {
+          return crow::response(crow::status::INTERNAL_SERVER_ERROR);
+        }
+
+        return crow::response(key);
+      });
+  CROW_ROUTE(app, "/<string>")
+      .methods(crow::HTTPMethod::Post)(
+          [api_key, trie](const crow::request &req, std::string s) {
+            AUTH();
+
+            bool res = ternarytrie_add(trie, s.c_str(), req.body.c_str());
+
+            if (!res) {
+              return crow::response(crow::status::CONFLICT);
+            }
+
+            return crow::response(crow::status::NO_CONTENT);
+          });
 
   app.port(18080).multithreaded().run();
 }

tries/include/ternarytrie.h

@@ -10,6 +10,12 @@
 #include <stdbool.h>
 #include <stddef.h>
 
+static const char charset[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
+static const size_t charset_len = sizeof(charset) - 1;
+
+// Length of randomly generated keys
+#define RANDOM_KEY_LENGTH 4
+
 /**
  * Type definition for the struct representing the current Trie.
  *
@@ -51,6 +57,14 @@ char * ternarytrie_search(TernaryTrie* trie, const char* string);
  */
 bool ternarytrie_add(TernaryTrie* trie, const char* string, const char *payload);
 
+/**
+ * Add a payload by generating a random string as the key.
+ *
+ * @param trie
+ * @return the generated key
+ */
+char *ternarytrie_add_random(TernaryTrie *trie, const char *payload);
+
 /**
  * Remove a string from this trie.
  *

tries/src/ternarytrie.c

@@ -1,14 +1,17 @@
-#include "ternarytrie.h"
-#include "ternarytrie_node.c"
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
+#include <pthread.h>
+
+#include "ternarytrie.h"
+#include "ternarytrie_node.c"
 
 typedef struct ttrie {
   TernaryTrieNode *root;
   size_t size;
   char* file_path;
+  pthread_rwlock_t lock;
 } TernaryTrie;
 
 /**
@@ -17,10 +20,11 @@ typedef struct ttrie {
  * @return pointer to the empty TernaryTrie
  */
 TernaryTrie *ternarytrie_init() {
-  TernaryTrie *node = calloc(1, sizeof(TernaryTrie));
-  node->root = ttnode_init();
+  TernaryTrie *trie = calloc(1, sizeof(TernaryTrie));
+  trie->root = ttnode_init();
+  pthread_rwlock_init(&trie->lock, NULL);
 
-  return node;
+  return trie;
 }
 
 /**
@@ -140,13 +144,19 @@ SearchResult ternarytrie_search_node(TernaryTrie *trie, const char *string) {
  * @return true if the string is present in the trie, false otherwise
  */
 char * ternarytrie_search(TernaryTrie *trie, const char *string) {
+  pthread_rwlock_rdlock(&trie->lock);
+
   SearchResult res = ternarytrie_search_node(trie, string);
   
+  char* return_value = NULL;
+
   if (res.child != NULL) {
-      return res.child->payload;
+      return_value = res.child->payload;
   }
 
-  return NULL;
+  pthread_rwlock_unlock(&trie->lock);
+
+  return return_value;
 }
 
 /**
@@ -240,10 +250,14 @@ bool ternarytrie_add_internal(TernaryTrie *trie, const char *string, const char
   return true;
 }
 
-bool ternarytrie_add(TernaryTrie *trie, const char *string, const char *payload) {
+bool ternarytrie_add_persistent(TernaryTrie *trie, const char *string, const char *payload) {
+  bool return_value = false;
+
   if (trie->file_path != NULL) {
     // Easiest way to make sure we don't add duplicate entries
-        if (ternarytrie_search(trie, string) != NULL) {
+    // We use an internal function that doesn't require a read lock, as we're
+    // already inside a write lock
+    if (ternarytrie_search_node(trie, string).child != NULL) {
       return false;
     }
 
@@ -261,9 +275,55 @@ bool ternarytrie_add(TernaryTrie *trie, const char *string, const char *payload)
     fclose(fp);
   }
 
+  // This function *should* always return true. Otherwise, the function would've
+  // exited because the string was found in the trie.
   return ternarytrie_add_internal(trie, string, payload);
 }
 
+bool ternarytrie_add(TernaryTrie *trie, const char *string, const char *payload) {
+  pthread_rwlock_wrlock(&trie->lock);
+
+  bool return_value = ternarytrie_add_persistent(trie, string, payload);
+
+  pthread_rwlock_unlock(&trie->lock);
+
+  return return_value;
+}
+
+char* ternarytrie_add_random(TernaryTrie *trie, const char *payload) {
+  pthread_rwlock_wrlock(&trie->lock);
+
+  // Generate random key
+  bool ok = false;
+  char *key = malloc(RANDOM_KEY_LENGTH + 1);
+  key[RANDOM_KEY_LENGTH] = '\0';
+
+  // We naively generate new keys until we find a key that isn't in the trie
+  // yet. With charset_len ** RANDOM_KEY_LENGTH sufficiently large, this isn't a
+  // problem, because the chances of collisions are extremely small.
+  while (!ok) {
+    for (int i = 0; i < RANDOM_KEY_LENGTH; i++) {
+      key[i] = charset[rand() % charset_len];
+    }
+
+    ok = ternarytrie_search_node(trie, key).child == NULL;
+  }
+
+  bool res = ternarytrie_add_persistent(trie, key, payload);
+  char *return_value;
+
+  if (res) {
+    return_value = key;
+  } else {
+    return_value = NULL;
+    free(key);
+  }
+
+  pthread_rwlock_unlock(&trie->lock);
+
+  return return_value;
+}
+
 
 /**
  * Remove the given string from a TernaryTrie.
@@ -273,13 +333,18 @@ bool ternarytrie_add(TernaryTrie *trie, const char *string, const char *payload)
  * @return true if the string was in the trie and thus removed, false otherwise
  */
 bool ternarytrie_remove(TernaryTrie *trie, const char *string) {
+  pthread_rwlock_wrlock(&trie->lock);
+
+  bool return_value = false;
+
   SearchResult res = ternarytrie_search_node(trie, string);
 
   if (res.child == NULL) {
-    return false;
+    goto end;
   }
 
   trie->size--;
+  return_value = true;
 
   if (res.parent != NULL) {
     // We're removing a full leaf, so we calculate the offset of the character
@@ -303,7 +368,7 @@ bool ternarytrie_remove(TernaryTrie *trie, const char *string) {
     } else {
       res.child->type = 0;
 
-      return true;
+      goto end;
     }
 
     ttnode_free(res.child);
@@ -313,7 +378,10 @@ bool ternarytrie_remove(TernaryTrie *trie, const char *string) {
     res.child->type = 0;
   }
 
-  return true;
+end:
+  pthread_rwlock_unlock(&trie->lock);
+
+  return return_value;
 }
 
 /**