Refactor code

backends/example.py

@@ -146,7 +146,8 @@ def get_paste_metadata_value(paste_id, key):
     passed are typically ASCII.
     :param paste_id: ASCII string which represents the ID of the paste
     :param key: key of the metadata
-    :return: value of the metadata key provided for the given ID, None if the key wasn't set
+    :return: value of the metadata key provided for the given ID, None if
+             the key wasn't set
     """
 
     if get_paste_metadata(paste_id)[key]:

backends/filesystem.py

@@ -44,12 +44,18 @@ def new_paste(paste_id, paste_content):
     ppath = "pastes/" + a + "/" + b + "/" + paste_id
 
     try:
-        with codecs.open(ppath, encoding = "utf-8", mode = "w+") as fd:
+        with codecs.open(
+            ppath,
+            encoding="utf-8",
+            mode="w+"
+        ) as fd:
             fd.write(paste_content)
     except:
         raise e.ErrorException(
-            "An issue occurred with the local filesystem. Please try again later. If the problem persists, \
-            try notifying a system administrator.")
+            "An issue occurred with the local filesystem. Please try again " +
+            "later. If the problem persists, try notifying a system " +
+            "administrator."
+        )
 
     return
 
@@ -84,17 +90,25 @@ def update_paste_metadata(paste_id, metadata):
                 os.remove("pastes/" + a + "/" + b + "/" + j)
     except:
         raise e.ErrorException(
-            "An issue occurred with the local filesystem. Please try again later. If the problem persists, \
-            try notifying a system administrator.")
+            "An issue occurred with the local filesystem. Please try again " +
+            "later. If the problem persists, try notifying a system " +
+            "administrator."
+        )
 
     try:
         for k, v in metadata.items():
-            with codecs.open(ppath + "." + k, encoding = "utf-8", mode = "w+") as fd:
+            with codecs.open(
+                ppath + "." + k,
+                encoding="utf-8",
+                mode="w+"
+            ) as fd:
                 fd.write(v)
     except:
         raise e.ErrorException(
-            "An issue occurred with the local filesystem. Please try again later. If the problem persists, \
-            try notifying a system administrator.")
+            "An issue occurred with the local filesystem. Please try again " +
+            "later. If the problem persists, try notifying a system " +
+            "administrator."
+        )
 
     return
 
@@ -128,12 +142,18 @@ def get_paste_contents(paste_id):
     b = paste_id[2:4]
 
     try:
-        with codecs.open("pastes/" + a + "/" + b + "/" + paste_id, encoding = "utf-8", mode = "r") as fd:
+        with codecs.open(
+            "pastes/" + a + "/" + b + "/" + paste_id,
+            encoding="utf-8",
+            mode="r"
+        ) as fd:
             return fd.read()
     except:
         raise e.ErrorException(
-            "An issue occurred with the local filesystem. Please try again later. If the problem persists, try \
-            notifying a system administrator.")
+            "An issue occurred with the local filesystem. Please try again " +
+            "later. If the problem persists, try notifying a system " +
+            "administrator."
+        )
 
 
 def get_paste_metadata(paste_id):
@@ -155,17 +175,25 @@ def get_paste_metadata(paste_id):
         for f in os.listdir("pastes/" + a + "/" + b + "/"):
             if (paste_id in f) and ("." in f):
                 t = f.split(".")[1]
-                with codecs.open("pastes/" + a + "/" + b + "/" + f, encoding = "utf-8", mode = "r") as fd:
+                with codecs.open(
+                    "pastes/" + a + "/" + b + "/" + f,
+                    encoding="utf-8",
+                    mode="r"
+                ) as fd:
                     ret[t] = fd.read()
     except:
         raise e.ErrorException(
-            "An issue occurred with the local filesystem. Please try again later. If the problem persists, \
-            try notifying a system administrator.")
+            "An issue occurred with the local filesystem. Please try again " +
+            "later. If the problem persists, try notifying a system " +
+            "administrator."
+        )
 
     if len(ret) == 0:
         raise e.WarningException(
-            "Failed to load Paste Metadata. Some features like the paste date may not work. If the problem persists, \
-            try notifying a system administrator.")
+            "Failed to load Paste Metadata. Some features like the paste " +
+            "date may not work. If the problem persists, try notifying a " +
+            "system administrator."
+        )
 
     return ret
 
@@ -179,7 +207,8 @@ def get_paste_metadata_value(paste_id, key):
     passed are typically ASCII.
     :param paste_id: ASCII string which represents the ID of the paste
     :param key: key of the metadata
-    :return: value of the metadata key provided for the given ID, None if the key wasn't set
+    :return: value of the metadata key provided for the given ID, None if
+             the key wasn't set
     """
 
     if get_paste_metadata(paste_id)[key]:
@@ -218,5 +247,7 @@ def get_all_paste_ids():
 
     except:
         raise e.ErrorException(
-            "An issue occurred with the local filesystem. Please try again later. If the problem persists, try \
-            notifying a system administrator.")
+            "An issue occurred with the local filesystem. Please try again " +
+            "later. If the problem persists, try notifying a system " +
+            "administrator."
+        )

logic.py

@@ -0,0 +1,127 @@
+#!bin/python
+
+import time
+from hashlib import sha256
+
+
+def format_size(size):
+    """
+    This method formats an arbitrary amount of bytes to a printable
+    string. For example 1024 will be converted to 1.0 kB.
+    :param size: an amount of bytes
+    :return: a string that's ready to be printed representing
+             approximately the amount of bytes in a human readable
+             way.
+    """
+    scales = ["bytes", "kB", "MB", "GB", "TB", "PB"]
+    count = 0
+    while (1 == 1):
+        if (size > 1024.0):
+            size /= 1024.0
+            count += 1
+        else:
+            break
+    return str(round(size, 1)) + " " + scales[count]
+
+
+def create_new_paste(content, config):
+    """
+    This method is responsible for creating new pastes by directly
+    talking to the currently used backend. It is also responsible
+    for ensuring the current input is valid, such as for example that
+    it is under the Maximum Allowed Paste Size.
+    :param content: The content of the paste to create
+    :param config: The TorPaste configuration object
+    :return: The result of the action (ERROR/OK), some data (error message/
+             Paste ID) as well as the suggested HTTP Status Code to return.
+    """
+    try:
+        paste_id = str(sha256(content.encode('utf-8')).hexdigest())
+    except:
+        return "ERROR", "An issue occured while handling the paste. " +\
+            "Please try again later. If the problem persists, try " +\
+            "notifying a system administrator."
+
+    if (len(content.encode('utf-8')) > config['MAX_PASTE_SIZE']):
+        return "ERROR", "The paste sent is too large. This TorPaste " +\
+            "instance has a maximum allowed paste size of " +\
+            format_size(config['MAX_PASTE_SIZE']) + "."
+
+    try:
+        config['b'].new_paste(paste_id, content)
+    except config['b'].e.ErrorException as errmsg:
+        return "ERROR", errmsg
+
+    try:
+        config['b'].update_paste_metadata(
+            paste_id,
+            {
+                "date": str(int(time.time()))
+            }
+        )
+    except config['b'].e.ErrorException as errmsg:
+        return "ERROR", errmsg
+
+    return "OK", paste_id
+
+
+def view_existing_paste(paste_id, config):
+    """
+    This method is responsible for checking if a paste with a given Paste ID
+    exists, and if it does, return its contents and needed metadata in order
+    for the View Paste view to work.
+    :param paste_id: The Paste ID to look for.
+    :param config: The TorPaste configuration object
+    :return: The result of the action (ERROR/WARNING/OK), some data (error
+             message / data tuple) as well as the suggested HTTP Status Code
+             to return.
+    """
+    if (not paste_id.isalnum()):
+        return "ERROR", "Invalid Paste ID. Please check the link " +\
+            "you used or use the Pastes button above.", 400
+
+    if (len(paste_id) != 64):
+        return "ERROR", "Paste ID has invalid length. Paste IDs " +\
+           "are 64 characters long. Please make sure the link you " +\
+           "clicked is correct or use the Pastes button above.", 400
+
+    if (not config['b'].does_paste_exist(paste_id)):
+        return "ERROR", "A paste with this Paste ID could not be " +\
+            "found. Sorry.", 404
+
+    try:
+        paste_content = config['b'].get_paste_contents(paste_id)
+    except config['b'].e.ErrorException as errmsg:
+        return "ERROR", errmsg, 500
+
+    try:
+        paste_date = config['b'].get_paste_metadata_value(paste_id, "date")
+    except config['b'].e.ErrorException as errmsg:
+        return "ERROR", errmsg, 500
+    except config['b'].e.WarningException as errmsg:
+        return "WARNING", errmsg, 500
+
+    return "OK", (paste_content, paste_date), 200
+
+
+def get_paste_listing(config):
+    """
+    This method is responsible for returning a list of all currently saved
+    pastes, or a list with only one element ("none") if there are no pastes.
+    :param config: The TorPaste configuration object
+    :return: A list with all Paste IDs of all stored pastes. If no stored
+             pastes exist, a list with only one element, "none".
+    """
+    if (not config['PASTE_LIST_ACTIVE']):
+        return "ERROR", "Paste listing has been disabled by the " +\
+            "administrator.", 503
+
+    try:
+        paste_list = config['b'].get_all_paste_ids()
+    except config['b'].e.ErrorException as errmsg:
+        return "ERROR", errmsg, 500
+
+    if (paste_list[0] == "none"):
+        return "OK", "none", 200
+
+    return "OK", paste_list, 200