Added btc_tracker.py and letter about Flask and threading.

btc_tracker.py

@@ -0,0 +1,5 @@
+import fetcher
+
+fetcher.start()
+
+exit(0)

btc_tracker/fetcher.py

@@ -0,0 +1,228 @@
+#!/usr/bin/python3
+
+import krakenex
+import json, sqlite3
+import requests, os, time
+import threading
+
+database = "btc_ohlc.db"
+
+def Checkthedatabase():
+  ## Some sanity for the database
+  # check if btc_timeseries.db database file exists
+  if not os.path.exists(database):
+    db = sqlite3.connect(database)
+    
+    db.execute("""\
+    CREATE TABLE ohlc (
+    id INTEGER PRIMARY KEY,
+    exchange TEXT NOT NULL,
+    timestamp INTEGER NOT NULL,
+    open REAL NOT NULL,
+    high REAL NOT NULL,
+    low REAL NOT NULL,
+    close REAL NOT NULL,
+    volume_quote REAL NOT NULL,
+    volume_base REAL NOT NULL,
+    trades INTEGER NOT NULL )""")
+
+    db.commit()
+    db.close()
+  
+  db = sqlite3.connect(database)
+  
+  # Check if the table exists
+  table_exists = False
+  cursor = db.execute("PRAGMA table_info(ohlc)")
+  for row in cursor:
+    table_exists = True
+  
+  # Create the table if it doesn't exist
+  if not table_exists:
+    db.execute("""\
+    CREATE TABLE ohlc (
+    id INTEGER PRIMARY KEY,
+    exchange TEXT NOT NULL,
+    timestamp INTEGER NOT NULL,
+    open REAL NOT NULL,
+    high REAL NOT NULL,
+    low REAL NOT NULL,
+    close REAL NOT NULL,
+    volume_quote REAL NOT NULL,
+    volume_base REAL NOT NULL,
+    trades INTEGER NOT NULL )""")
+    db.commit()
+
+def fetch_kraken():
+### Kraken
+  kraken = krakenex.API()
+  
+  response = kraken.query_public('OHLC', {'pair': 'BTCUSD', 'interval': 240 })
+  ohlc_data = response['result']['XXBTZUSD']
+  
+  candle_stick_data = {
+      'exchange': 'kraken',
+      'timestamp': ohlc_data[1][0],
+      'open': ohlc_data[0][1],
+      'high': max(item[2] for item in ohlc_data),
+      'low': min(item[3] for item in ohlc_data),
+      'close': ohlc_data[-1][4],
+      'volume_quote': sum(float(item[5]) for item in ohlc_data),
+      'volume_base': sum(float(item[6]) for item in ohlc_data),
+      'trades': sum(item[7] for item in ohlc_data),
+  }
+  
+  kraken_json = json.dumps(candle_stick_data, indent=2)
+  #print("Kraken: OK")
+  #print(kraken_json)
+  #q.put("Kraken: OK")
+  return kraken_json
+
+def fetch_bitstamp(q):
+## Bitstamp
+  response = requests.get("https://www.bitstamp.net/api/v2/ohlc/btcusd/?step=300&limit=1")
+  
+  if response.status_code == 200:  # check if the request was successful
+    bitstamp_data = response.json()
+    ohlc_data = bitstamp_data["data"]["ohlc"]
+    
+    candle_stick_data = {
+        'exchange': 'bitstamp',
+        'timestamp': int(ohlc_data[0]['timestamp']),
+        'open': float(ohlc_data[0]['open']),
+        'high': float(ohlc_data[0]['high']),
+        'low': float(ohlc_data[0]['low']),
+        'close': float(ohlc_data[0]['close']),
+        'volume_quote': float(ohlc_data[0]['volume']),
+        'volume_base': 0,  # not provided by Bitstamp API
+        'trades': 0,  # not provided by Bitstamp API
+    }
+    
+    bitstamp_json = json.dumps(candle_stick_data, indent=2)
+    #print("Bitstamp: OK")
+    #print(bitstamp_json)
+    #q.put("Bitstamp: OK")
+    return bitstamp_json
+  else:
+    print(f"Error fetching data from Bitstamp API: {response.status_code}")
+    q.put("Bitstamp: ERROR")
+    return empty_json
+
+def fetch_bitfinex(q):
+## Bitfinex
+  response = requests.get("https://api-pub.bitfinex.com/v2/candles/trade:5m:tBTCUSD/last")
+  
+  if response.status_code == 200:  # check if the request was successful
+    ohlc_data = response.json()
+    candle_stick_data = {
+        'exchange': 'bitfinex',
+        'timestamp': ohlc_data[0],
+        'open': ohlc_data[1],
+        'high': ohlc_data[2],
+        'low': ohlc_data[3],
+        'close': ohlc_data[4],
+        'volume_quote': ohlc_data[5],
+        'volume_base': 0,  # not provided by Bitfinex API
+        'trades': 0,  # not provided by Bitfinex API
+    }
+    
+    bitfinex_json = json.dumps(candle_stick_data, indent=2)
+    #print("Bitfinex: OK")
+    #print(bitfinex_json)
+    #q.put("Bitfinex: OK")
+    return bitfinex_json
+  else:
+    print(f"Error fetching data from Bitfinex API: {response.status_code}")
+    q.put("Bitfinex: ERROR")
+    return empty_json
+
+def fetch_gemini(q):
+## Gemini
+  response = requests.get("https://api.gemini.com/v2/candles/btcusd/5m")
+  
+  if response.status_code == 200:  # check if the request was successful
+    gemini_ohlc = response.json()
+    candle_stick_data = {
+        'exchange': 'gemini',
+        'timestamp': gemini_ohlc[0][0],
+        'open': gemini_ohlc[0][1],
+        'high': gemini_ohlc[0][2],
+        'low': gemini_ohlc[0][3],
+        'close': gemini_ohlc[0][4],
+        'volume_quote': 0,  # not provided by Gemini API
+        'volume_base': gemini_ohlc[0][5],
+        'trades': 0,  # not provided by Gemini API
+    }
+    gemini_json = json.dumps(candle_stick_data, indent=2)
+    #print("Gemini: OK")
+    #print(gemini_json)
+    #q.put("Gemini: OK")
+    return gemini_json
+  else:
+    print(f"Error fetching data from Gemini API: {response.status_code}")
+    q.put("Gemini: ERROR")
+    return empty_json
+
+def write_dict_to_database(in_dict, connection):
+  cursor = connection.cursor()
+  # Use placeholders for the values in the INSERT statement
+  insert_query = "INSERT INTO ohlc (exchange, timestamp, open, high, low, close, volume_quote, volume_base, trades) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)"
+
+  values = (in_dict['exchange'], 
+            in_dict['timestamp'], 
+            in_dict['open'], 
+            in_dict['high'], 
+            in_dict['low'], 
+            in_dict['close'], 
+            in_dict['volume_quote'], 
+            in_dict['volume_base'], 
+            in_dict['trades'])
+  ## apply lock while writing to database
+  with database_lock:
+    cursor.execute(insert_query, values)
+    connection.commit()
+
+def get_the_data(q):
+   #cursor = db.cursor()
+   while True:  
+    #logline = "Fetching at: " + str(time.time())
+    #q.put(logline)
+    db = sqlite3.connect(database)
+    write_dict_to_database(json.loads(fetch_kraken()), db)
+    write_dict_to_database(json.loads(fetch_bitfinex(q)), db)
+    write_dict_to_database(json.loads(fetch_bitstamp(q)), db)
+    write_dict_to_database(json.loads(fetch_gemini(q)), db)
+    db.close()
+    time.sleep(290)
+    
+
+Checkthedatabase()
+
+# Empty response json
+empty_dict = {"exchange": "", "timestamp": 0, "open": 0, "high": 0, "low": 0, "close": 0, "volume_quote": 0, "volume_base": 0, "trades": 0}
+empty_json = json.dumps(empty_dict)
+database_lock = threading.Lock()
+
+fetch_thread = threading.Thread()
+def get_health():
+  if fetch_thread.is_alive():
+    return "Alive"
+  else:
+    return "Dead"
+
+def start(q):
+  logline = "Started at " + str(time.time())
+  q.put(logline)
+  fetch_thread.target = get_the_data
+  fetch_thread.args = (q, )
+  fetch_thread.daemon = True
+  fetch_thread.start()
+  logline = "Fetcher ID: " + str(fetch_thread.ident) + " or " + str(fetch_thread.native_id)
+  q.put(logline)
+
+  db = sqlite3.connect(database)
+  lastID_andTime = db.execute("SELECT id, timestamp FROM ohlc LIMIT 1 OFFSET (SELECT COUNT(*) FROM ohlc) - 1").fetchall()
+  #q.put(json.dumps(lastID_andTime, indent=2, separators=(',', ':')))
+  q.put(json.dumps(lastID_andTime, separators=(',', ':')))
+
+

btc_tracker/kraken_fetch.py

@@ -103,7 +103,7 @@ def fetch_bitstamp():
     return bitstamp_json
   else:
     print(f"Error fetching data from Bitstamp API: {response.status_code}")
-    return "Bitstamp: ERROR"
+    return empty_json
 
 def fetch_bitfinex():
 ## Bitfinex
@@ -129,7 +129,7 @@ def fetch_bitfinex():
     return bitfinex_json
   else:
     print(f"Error fetching data from Bitfinex API: {response.status_code}")
-    return "Bitfinex: ERROR"
+    return empty_json
 
 def fetch_gemini():
 ## Gemini
@@ -154,7 +154,7 @@ def fetch_gemini():
     return gemini_json
   else:
     print(f"Error fetching data from Gemini API: {response.status_code}")
-    return "Gemini: ERROR"
+    return empty_json
 
 def write_dict_to_database(in_dict, connection):
   cursor = connection.cursor()
@@ -189,6 +189,10 @@ def get_the_data():
 
 Checkthedatabase()
 
+# Empty response json
+empty_dict = {"exchange": "", "timestamp": 0, "open": 0, "high": 0, "low": 0, "close": 0, "volume_quote": 0, "volume_base": 0, "trades": 0}
+empty_json = json.dumps(empty_dict)
+
 database_lock = threading.Lock()
 # make this run in thread and allow contium to http api stuff
 fetch_thread = threading.Thread(target=get_the_data)
@@ -200,7 +204,7 @@ count = 1
 while True:
   if count % 10 == 0:
     print("------- status ", count, "-------")
-    top2_rows = db.execute("SELECT * FROM ohlc LIMIT 2").fetchall()
+    top2_rows = db.execute("SELECT * FROM ohlc LIMIT 2 OFFSET (SELECT COUNT(*) FROM ohlc) - 2").fetchall()
     print(json.dumps(top2_rows, indent=4))
   else:
     output = str(count) + ".. "

btc_tracker/the_server.py

@@ -0,0 +1,31 @@
+#!/usr/bin/python3
+import fetcher
+import time
+from queue import Queue
+from flask import Flask
+
+
+# Create a queue to get some info how the fetcher is doing
+q = Queue()
+# Start the data collecting
+fetcher.start(q)
+
+# Initialize the Flask app
+app = Flask(__name__)
+
+@app.route("/")
+def root():
+  if not q.empty():
+    data = q.get()
+    return(str(data))
+  else:
+    return("Fetcher message queue is empty")
+
+@app.route("/fetcher_health")
+def fetcher_health():
+  health = fetcher.get_health()
+  return(str(health))
+
+# Run the app
+if __name__ == "__main__":
+  app.run()

letters/Flask_and_backend_process.py

@@ -0,0 +1,62 @@
+from flask import Flask
+import threading
+import sqlite3
+
+app = Flask(__name__)
+
+# Create a lock for synchronizing access to the database
+lock = threading.Lock()
+
+def my_background_process():
+    # Acquire the lock
+    lock.acquire()
+
+    # Connect to the in-memory database
+    conn = sqlite3.connect(':memory:')
+    c = conn.cursor()
+
+    # Create a table in the database
+    c.execute("CREATE TABLE mytable (col1 INTEGER, col2 TEXT)")
+
+    # Write to the database
+    c.execute("INSERT INTO mytable (col1, col2) VALUES (?, ?)", (value1, value2))
+    conn.commit()
+
+    # Close the connection
+    conn.close()
+
+    # Release the lock
+    lock.release()
+
+@app.route('/')
+def read_from_database():
+    # Acquire the lock
+    lock.acquire()
+
+    # Connect to the in-memory database
+    conn = sqlite3.connect(':memory:')
+    c = conn.cursor()
+
+    # Read from the database
+    c.execute("SELECT * FROM mytable")
+    rows = c.fetchall()
+
+    # Close the connection
+    conn.close()
+
+    # Release the lock
+    lock.release()
+
+    # Return the rows to the client
+    return rows
+
+if __name__ == '__main__':
+    # Create a new thread for the background process
+    thread = threading.Thread(target=my_background_process)
+
+    # Start the thread
+    thread.start()
+
+    # Start the Flask app
+    app.run()
+