readValue(): refactoring

Author: JulStrat

README.md

@@ -22,12 +22,16 @@ int readValue(void *buff, unsigned int byteNum);
 cdbResult close();
 ```    
 
-## Usage example
+## Usage examples
 
 `examples` folder contains `airports.ino` Arduino IDE sketch, Python converter `airports.py` script and data files.
 
 <img src="https://github.com/JulStrat/uCDB/blob/master/examples/airports/airports.png">
 
+`benchmark` sketch.
+
+<img src="https://github.com/JulStrat/uCDB/blob/master/examples/benchmark/benchmark.png">
+
 ## License
 
 `uCDB` source code released into the public domain.

examples/benchmark/benchmark.ino

@@ -35,6 +35,7 @@ void loop() {
   long key;
   unsigned long startMillis;  
   cdbResult rt;
+  int br;
 
   Serial.println("Press any key to start test");
   while (!Serial.available()) {
@@ -47,7 +48,7 @@ void loop() {
     return;
   }
 
-  Serial.println("Querying 1000 random keys from interval [0..5000000)...");
+  Serial.println("Querying 1000 random keys from interval [0, 5000000)...");
   startMillis = millis();
   for (int i = 0; i < 1000; ++i) {
     key = random(5000000);
@@ -71,7 +72,7 @@ void loop() {
   Serial.print("Query millis: ");
   Serial.println(millis() - startMillis);
 
-  Serial.println("Querying 1000 random keys from interval [-5000000,0)...");
+  Serial.println("Querying 1000 random keys from interval [-5000000, 0)...");
   startMillis = millis();
   for (int i = 0; i < 1000; ++i) {
     key = random(-5000000, 0);
@@ -86,7 +87,7 @@ void loop() {
   Serial.print("Query millis: ");
   Serial.println(millis() - startMillis);
 
-  Serial.println("Querying 1000 random keys with findNextValue() from interval [0..5000000)...");
+  Serial.println("Querying 1000 random keys with findNextValue() from interval [0, 5000000)...");
   startMillis = millis();
   for (int i = 0; i < 1000; ++i) {
     key = random(5000000);
@@ -116,7 +117,7 @@ void loop() {
   Serial.print("Query millis: ");
   Serial.println(millis() - startMillis);
 
-  Serial.println("Querying 1000 random keys with findNextValue() from interval [-5000000,0)...");
+  Serial.println("Querying 1000 random keys with findNextValue() from interval [-5000000, 0)...");
   startMillis = millis();
   for (int i = 0; i < 1000; ++i) {
     key = random(-5000000, 0);
@@ -137,6 +138,24 @@ void loop() {
   Serial.print("Query millis: ");
   Serial.println(millis() - startMillis);
 
+  Serial.println("readValue() test...");
+  for (int i = 0; i < 100; ++i) {
+    sprintf(str, "%ld", (long)5*i);
+    rt = ucdb.findKey(str, strlen(str));
+
+    if (rt == KEY_FOUND) {
+      br = ucdb.readValue(str, 15);
+      if (br >= 0) {
+        str[br] = '\0';
+        Serial.println(str);
+      }
+    }
+    else {
+      Serial.print("Error: ");
+      Serial.println(5*i);
+      break;
+    }
+  }
 
   ucdb.close();
   while (Serial.available()) {

examples/benchmark/benchmark.png

@@ -207,16 +207,20 @@ int uCDB::readValue() {
 }
 
 int uCDB::readValue(void *buff, unsigned int byteNum) {
-  if (state != KEY_FOUND) {
-    return -1;
-  }
+  int br;
 
-  if (byteNum > valueBytesAvail) {
-    byteNum = valueBytesAvail;
+  if (state == KEY_FOUND) {
+    if (byteNum > valueBytesAvail) {
+      byteNum = valueBytesAvail;
+    }
+    br = cdb.read(buff, byteNum);
+    if (br > 0) {
+      valueBytesAvail -= br;  
+    }
+    return br;
   }
-  valueBytesAvail -= byteNum;
 
-  return cdb.read(buff, byteNum);
+  return -1;
 }
 
 cdbResult uCDB::close() {