recordsNumber(): state check fix.

README.md

@@ -4,12 +4,18 @@
 # uCDB
 
 Arduino library for querying [Constant DataBase](https://en.wikipedia.org/wiki/Cdb_(software)) (key, value) store.
-Simple, fast and portable CDB file format was developed by D. J. Bernstein.
+Simple, :cyclone: fast and portable CDB file format was developed by D. J. Bernstein.
+
+Compatible storage libraries:
+- official [Arduino SD](https://github.com/arduino-libraries/SD)
+- [Greiman SdFat](https://github.com/greiman/SdFat)
+- [SdFat - Adafruit fork](https://github.com/adafruit/SdFat)
+- [Adafruit SPIFlash](https://github.com/adafruit/Adafruit_SPIFlash)
 
 ## API
 
 ```C++
-cdbResult open(const char fileName[], unsigned long (*userHashFunc)(const void *key, unsigned long keyLen) = DJBHash);
+cdbResult open(const char *fileName, unsigned long (*userHashFunc)(const void *key, unsigned long keyLen) = DJBHash);
 
 cdbResult findKey(const void *key, unsigned long keyLen);
 

examples/benchmark/benchmark.ino

@@ -1,16 +1,16 @@
 /*
   uCDB benchmark sketch
-  
+
   Write file bench.cdb ([0..5000000] divisible by 5) on SD card. Connect to Ardino board.
   Compile and upload sketch. Open Serial Monitor.
-  
+
   Board: Arduino Uno
   SD card: SDHC 7.31Gb FAT32, sectorsPerCluster - 64
   SD chip select pin: 10
   Arduino IDE Serial Monitors settings: 9600 baud, no line ending.
 
   Created by Ioulianos Kakoulidis, 2021.
-  Released into the public domain.     
+  Released into the public domain.
 */
 
 //#define USE_SERIALFLASH_LIB
@@ -30,14 +30,12 @@ SdFat fat;
 uCDB<SdFat, File> ucdb(fat);
 #endif
 
-
-
 void setup() {
   Serial.begin(9600);
   while (!Serial) {
     ;
   }
-  
+
   if (!fat.begin(10)) {
     Serial.println("SD card initialization failed!");
     while (true) {
@@ -47,18 +45,17 @@ void setup() {
 }
 
 void loop() {
-
   char str[16];
   long key;
-  unsigned long startMillis;  
+  unsigned long startMillis;
   cdbResult rt;
   int br;
 
   Serial.println("Press any key to start test");
   while (!Serial.available()) {
     ;
   }
-  
+
   if (ucdb.open("bench.cdb") != CDB_OK) {
     Serial.print("Invalid CDB: ");
     Serial.println("bench.cdb");
@@ -106,7 +103,7 @@ void loop() {
   }
   Serial.print("Query millis: ");
   Serial.println(millis() - startMillis);
-  
+
   Serial.println("Querying 1000 random keys with findNextValue() from interval [0, 5000000)...");
   startMillis = millis();
   for (int i = 0; i < 1000; ++i) {
@@ -136,7 +133,7 @@ void loop() {
   }
   Serial.print("Query millis: ");
   Serial.println(millis() - startMillis);
-  
+
   Serial.println("Querying 1000 random keys with findNextValue() from interval [-5000000, 0)...");
   startMillis = millis();
   for (int i = 0; i < 1000; ++i) {
@@ -183,4 +180,4 @@ void loop() {
   while (Serial.available()) {
     Serial.read();
   }
-}
+}

library.properties

@@ -1,5 +1,5 @@
 name=uCDB
-version=0.4.3
+version=0.5.0
 author=Ioulianos Kakoulidis
 maintainer=Ioulianos Kakoulidis <[email protected]>
 sentence=API for querying Constant DataBase file store.

src/uCDB.hpp

@@ -3,7 +3,7 @@
    uCDB template implementation
 
    @author    Ioulianos Kakoulidis
-   @date      2021   
+   @date      2021
    @copyright Public Domain
 */
 
@@ -53,7 +53,7 @@ class uCDB
         after successful finKey() or findNextValue() call
     */
     int readValue(void *buff, unsigned int byteNum);
-    
+
     /**
         Total records number in CDB
     */
@@ -120,7 +120,7 @@ static unsigned long unpack(const byte *buff);
 
 template <class TFileSystem, class TFile>
 uCDB<TFileSystem, TFile>::uCDB(TFileSystem& fs) : fs_(fs) {
-  zero();  
+  zero();
   state = CDB_CLOSED;
 }
 
@@ -131,9 +131,9 @@ cdbResult uCDB<TFileSystem, TFile>::open(const char *fileName, unsigned long (*u
 
   unsigned long dend;
   unsigned long snum;
-  
+
   byte buff[CDB_DESCRIPTOR_SIZE];
-  
+
   zero();
   if (cdb) {
     cdb.close(); // Close previously opened CDB file
@@ -147,9 +147,9 @@ cdbResult uCDB<TFileSystem, TFile>::open(const char *fileName, unsigned long (*u
   if (!cdb) {
     return (state = CDB_CLOSED);
   }
-  
+
   // CDB hash tables position and slots number integrity check
-  
+
   // CDB file size must be at least HEADER_SIZE bytes
   if (cdb.size() < CDB_HEADER_SIZE) {
     return (state = CDB_ERROR);
@@ -170,27 +170,27 @@ cdbResult uCDB<TFileSystem, TFile>::open(const char *fileName, unsigned long (*u
       continue; // Empty hash table
     }
     if ((htPos < CDB_HEADER_SIZE) || (htPos > cdb.size())) {
-      return (state = CDB_ERROR); // Critical CDB format or data integrity error          
+      return (state = CDB_ERROR); // Critical CDB format or data integrity error
     }
     if (((cdb.size() - htPos) >> 3) < htSlotsNum) {
-      return (state = CDB_ERROR); // Critical CDB format or data integrity error          
+      return (state = CDB_ERROR); // Critical CDB format or data integrity error
     }
-    
+
     // Adjust data end position and total slots number
     if (htPos < dend) {
       dend = htPos;
     }
     snum += htSlotsNum;
 
     if (((cdb.size() - dend) >> 3) < snum) {
-      return (state = CDB_ERROR); // Critical CDB format or data integrity error          
+      return (state = CDB_ERROR); // Critical CDB format or data integrity error
     }
   }
   // Check total
   if ((cdb.size() - dend) != 8 * snum){
-    return (state = CDB_ERROR); // Critical CDB format or data integrity error           
+    return (state = CDB_ERROR); // Critical CDB format or data integrity error
   }
-  
+
   dataEndPos = dend;
   slotsNum = snum;
   hashFunc = userHashFunc;
@@ -245,14 +245,14 @@ cdbResult uCDB<TFileSystem, TFile>::findNextValue() {
   }
 
   while (slotsToScan) {
-    rd = readDescriptor(buff, nextSlotPos);  
+    rd = readDescriptor(buff, nextSlotPos);
     // Adjust slotsToScan and next slot position
     --slotsToScan;
     nextSlotPos += CDB_DESCRIPTOR_SIZE;
     if (nextSlotPos == hashTabEndPos) {
       nextSlotPos = hashTabStartPos;
     }
-    
+
     if (!rd) {
       return (state = FILE_ERROR);
     }
@@ -267,7 +267,7 @@ cdbResult uCDB<TFileSystem, TFile>::findNextValue() {
 
     // Check data position
     if ((dataPos < CDB_HEADER_SIZE) || (dataPos > (dataEndPos - CDB_DESCRIPTOR_SIZE))) {
-      return (state = CDB_ERROR); // Critical CDB format or data integrity error          
+      return (state = CDB_ERROR); // Critical CDB format or data integrity error
     }
 
     if (slotHash == keyHash) {
@@ -277,27 +277,27 @@ cdbResult uCDB<TFileSystem, TFile>::findNextValue() {
 
       dataKeyLen = unpack(buff);
       dataValueLen = unpack(buff + 4);
-      
+
       //> key, value length check
       unsigned long t = dataPos + CDB_DESCRIPTOR_SIZE;
       if ((dataEndPos - t) < dataKeyLen) {
-        return (state = CDB_ERROR); // Critical CDB format or data integrity error          
+        return (state = CDB_ERROR); // Critical CDB format or data integrity error
       }
       t += dataKeyLen;
       if ((dataEndPos - t) < dataValueLen) {
-        return (state = CDB_ERROR); // Critical CDB format or data integrity error          
+        return (state = CDB_ERROR); // Critical CDB format or data integrity error
       }
       //< key, value length check
 
       if (keyLen_ == dataKeyLen) {
         switch (compareKey()) {
           case KEY_FOUND:
-            valueBytesAvail = dataValueLen;          
-            return (state = KEY_FOUND);             
+            valueBytesAvail = dataValueLen;
+            return (state = KEY_FOUND);
           case FILE_ERROR:
-            return (state = FILE_ERROR);             
+            return (state = FILE_ERROR);
           default:
-            ;          
+            ;
         }
       }
     }
@@ -329,7 +329,7 @@ int uCDB<TFileSystem, TFile>::readValue(void *buff, unsigned int byteNum) {
     }
     int br = cdb.read(buff, byteNum);
     if (br > 0) {
-      valueBytesAvail -= br;  
+      valueBytesAvail -= br;
     }
     return br;
   }
@@ -339,7 +339,15 @@ int uCDB<TFileSystem, TFile>::readValue(void *buff, unsigned int byteNum) {
 
 template <class TFileSystem, class TFile>
 unsigned long uCDB<TFileSystem, TFile>::recordsNumber() {
-  return (slotsNum >> 1);  
+  // Check CDB state
+  switch (state) {
+    case CDB_CLOSED:
+    case CDB_NOT_FOUND:
+    case CDB_ERROR:
+      return 0;
+    default:
+      return (slotsNum >> 1);
+  }
 }
 
 template <class TFileSystem, class TFile>
@@ -349,7 +357,7 @@ unsigned long uCDB<TFileSystem, TFile>::valueAvailable() {
 
 template <class TFileSystem, class TFile>
 cdbResult uCDB<TFileSystem, TFile>::close() {
-  zero();  
+  zero();
   if (cdb) {
     cdb.close();
   }
@@ -386,10 +394,11 @@ cdbResult uCDB<TFileSystem, TFile>::compareKey() {
 
   return KEY_FOUND;
 }
+
 template <class TFileSystem, class TFile>
 bool uCDB<TFileSystem, TFile>::readDescriptor(byte *buff, unsigned long pos) {
   if (cdb.position() != pos) {
-    cdb.seek(pos);  
+    cdb.seek(pos);
     if (pos != cdb.position()) {
       return false;
     }
@@ -400,14 +409,11 @@ bool uCDB<TFileSystem, TFile>::readDescriptor(byte *buff, unsigned long pos) {
 
 template <class TFileSystem, class TFile>
 void uCDB<TFileSystem, TFile>::zero() {
-  dataEndPos = 0;
-  slotsNum = 0;
-
   slotsToScan = 0;
   nextSlotPos = 0;
 }
 
-#define DJB_START_HASH 5381UL  
+#define DJB_START_HASH 5381UL
 unsigned long DJBHash(const void *key, unsigned long keyLen) {
   unsigned long h = DJB_START_HASH;
   const byte *curr = static_cast<const byte *>(key);