You have several different rights -
First, there is the statute of limitations. That's how long the DA has to file charges. On most felonies, it's three years. On misdemeanors, it's one year.
Next, you have a right to a speedy trial, but that only kicks in after the arraignment and entry of your not guilty plea.
The more time that goes by could be a good thing - they may be figuring out there's not enough evidence to charge you.... or they could be building a case against you.
Keep protecting your rights - make court appearances if you've been ordered to appear and keep quiet about whatever this incident is. If they don't have a case, don't help them out by saying something to actually give them a case.
You cannot have charges dismissed if you are never charged!! This would be the best outcome at this point that you could hope for. You can be arrested on suspicion of particular crimes, however, it is up to the District Attorney to view the evidence and decide what charges, if any, should be filed against you. If you are never charged with anything it is just as if nothing has happened. There is a time limit that the DA has as to how long they can take to file charges, but that limitation varies depending on the charges and whether they are misdemeanor or felony.
Should they not file charges you would have nothing on your record. At that point, you may want to also contact a lawyer about trying to have your arrest deemed a detention, because the arrest at that point would be the only thing that may potentially show up in your past.
In Fresno County the Court will make you appear several times on your bond if charges are not filed. Eventually, the court will exhonerate the bond and you will not have to go back to court if the DA doesn't file charges. This does not preclude the DA from eventually filing charges though.
The statute of limitiations (how long the District Attorney has to file charges) in most felony cases is three years.
Even if the court tells you that you no longer have to come back becasue the District Attorney hasn't filed charges that doesn't preclude the District Attorney from filing charges sometime within the next three years. Also, for some crimes the statute of limitations is even longer than three years.
Regarding speedy trial rights. . . You do have a right to a speedy trial; however, that doesn't begin until and if the District Attorney files charges against you. If they do file felony charges you have a right to a preliminary hearing within 10 days. Assuming you are held to answer the arraignment on the Information would be scheduled 15 days later. The trial would then have to be held within 60 days of the arraignment on the Information. This whole process is about 3 months and to delay your case beyond this you would have to agree.
If misdemeanor charges are filed you have a right to a trial within 45 days (assuming you remain out of custody on the bond you posted).
The best case scenario for you is that charges never get filed. Do you currently have an attorney? If not, I would hire one. Sometimes having an attorney involved before the case is filed results in charges never being filed. The attorney should be able to discuss your matter with the District Attorney, provide your version of the events, and may ultimately desuade the District Attorney from filing charges.