Left-hander Jeremy Affeldt has been given a one-year extension through 2011 that adds $5.5 million in new money.
In all, the team added $43.25 million in new commitments in the three deals.
Cain gets a $1 million signing bonus, $4.5 million this year, $7 million in 2011 and $15 million in 2012. He was due to make $4.5 million in 2010, the final season of a $9 million, four-year contract that included a $6.25 million team option for 2011.
Depending on how he does in Cy Young Award voting, Cain's salary could escalate to $7.5 million in 2011 and $15.5 million in 2012. He would earn a $50,000 bonus each year he pitches 225 innings and gets a limited no-trade provision giving him the right to block deals to eight teams.
Cain was a first-time All-Star last year and went 14-8 with a 2.89 ERA in 33 starts. His four complete games tied for first in the NL.
"It just shows appreciation for the things I've done, and the way they run the organization," Cain said. "It shows that we can do something to benefit both sides."
The 25-year-old showed he is nearly ready for the regular season on Sunday by pitching five innings of no-hit ball in a minor league game. He gave up two home runs in the sixth and pitched the seventh.
Wilson, 28, already was signed for $4,437,500 for this year under a settlement in January that avoided salary arbitration. The extension added salaries of $6.5 million in 2011 and $8.5 million in 2012.
He had 38 saves last season and 41 in 2008. He was a first-time All-Star in 2008.
The 30-year-old Affeldt receives a $500,000 raise to $4.5 million this season, gets $4.5 million in 2011 and has a $5 million club option for 2012 with a $500,000 buyout.
He tied with Minnesota's Matt Guerrier for the major league lead in holds with 33 last season.
In February, the Giants and two-time Cy Young Award winner Tim Lincecum finalized a $23 million, two-year deal.
"It's what we've been talking about all spring," Cain said of the Giants' rotation. "We love playing together. We all feed off each other.
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