What is the effect of section 1170.18 of the California Penal Code on drug possession and drug dealing?

The Act "makes certain drug- and theft-related offenses misdemeanors, unless the offenses were committed by certain ineligible defendants. These offenses had previously been designated as either felonies or wobblers (crimes that can be punished as either felonies or misdemeanors)." (People v. Rivera (2015) 233 Cal.App.4th 1085, 1091.) The Act also added section 1170.18 to the Penal Code, which provides: "A person currently serving a sentence for a conviction, whether by trial or plea, of a felony or felonies who would have been guilty of a misdemeanor under the act that added this section ('this act') had this act been in effect at the time of the offense may petition for a recall of sentence before the trial court that entered the judgment of conviction in his or her case to request resentencing."