Modify eeprom.py to support cache

platform/broadcom/sonic-platform-modules-accton/as7726-32x/sonic_platform/eeprom.py

@@ -2,13 +2,87 @@
 
 try:
     from sonic_platform_pddf_base.pddf_eeprom import PddfEeprom
+    import os
 except ImportError as e:
     raise ImportError(str(e) + "- required module not found")
 
+CACHE_ROOT = '/var/cache/sonic/decode-syseeprom'
+CACHE_FILE = 'syseeprom_cache'
 
 class Eeprom(PddfEeprom):
+    _TLV_INFO_MAX_LEN = 256
+    pddf_obj = {}
+    plugin_data = {}
 
     def __init__(self, pddf_data=None, pddf_plugin_data=None):
-        PddfEeprom.__init__(self, pddf_data, pddf_plugin_data)
+        #PddfEeprom.__init__(self, pddf_data, pddf_plugin_data)
+        if not pddf_data or not pddf_plugin_data:
+            raise ValueError('PDDF JSON data error')
+
+        self.pddf_obj = pddf_data
+        self.plugin_data = pddf_plugin_data
+
+        # system EEPROM always has device name EEPROM1
+        self.eeprom_path = self.pddf_obj.get_path("EEPROM1", "eeprom")
+        if self.eeprom_path is None:
+            return
+
+        super(PddfEeprom, self).__init__(self.eeprom_path, 0, '', True)
+        self.eeprom_tlv_dict = dict()
+
+        # Create the cache directory if not created
+        if not os.path.exists(CACHE_ROOT):
+            try:
+                os.makedirs(CACHE_ROOT)
+            except Exception as e:
+                print("Error in creating Eeprom cache directory - {}".format(str(e)))
+
+        # Assign cache_name in eeprom_base.py
+        try:
+            self.set_cache_name(os.path.join(CACHE_ROOT, CACHE_FILE))
+        except:
+            pass
+
+        try:
+            self.eeprom_data = self.read_eeprom()
+        except Exception as e:
+            self.eeprom_data = "N/A"
+            raise RuntimeError("Eeprom is not Programmed - Error: {}".format(str(e)))
+        else:
+            eeprom = self.eeprom_data
+
+            try:
+                self.update_cache(eeprom)
+            except:
+                pass
+
+            if not self.is_valid_tlvinfo_header(eeprom):
+                return
+
+            total_length = ((eeprom[9]) << 8) | (eeprom[10])
+            tlv_index = self._TLV_INFO_HDR_LEN
+            tlv_end = self._TLV_INFO_HDR_LEN + total_length
+
+            while (tlv_index + 2) < len(eeprom) and tlv_index < tlv_end:
+                if not self.is_valid_tlv(eeprom[tlv_index:]):
+                    break
+
+                tlv = eeprom[tlv_index:tlv_index + 2
+                             + (eeprom[tlv_index + 1])]
+                code = "0x%02X" % ((tlv[0]))
+
+                if (tlv[0]) == self._TLV_CODE_VENDOR_EXT:
+                    value = str(((tlv[2]) << 24) | ((tlv[3]) << 16) |
+                                ((tlv[4]) << 8) | (tlv[5]))
+                    value += str(tlv[6:6 + (tlv[1])])
+                else:
+                    name, value = self.decoder(None, tlv)
+
+                self.eeprom_tlv_dict[code] = value
+                if (eeprom[tlv_index]) == self._TLV_CODE_CRC_32:
+                    break
+
+                tlv_index += (eeprom[tlv_index+1]) + 2
+
 
     # Provide the functions/variables below for which implementation is to be overwritten