Internal call graph ▾

In the call graph viewer below, each node is a function belonging to this package and its children are the functions it calls—perhaps dynamically.

The root nodes are the entry points of the package: functions that may be called from outside the package. There may be non-exported or anonymous functions among them if they are called dynamically from another package.

Click a node to visit that function's source code. From there you can visit its callers by clicking its declaring func token.

Functions may be omitted if they were determined to be unreachable in the particular programs or tests that were analyzed.

▾ Example

Code:

package riff_test

import (
    "fmt"
    "io"
    "io/ioutil"
    "log"
    "strings"

    "golang.org/x/image/riff"
)

func ExampleReader() {
    formType, r, err := riff.NewReader(strings.NewReader(data))
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("RIFF(%s)\n", formType)
    if err := dump(r, ".\t"); err != nil {
        log.Fatal(err)
    }
    // Output:
    // RIFF(ROOT)
    // .	ZERO ""
    // .	ONE  "a"
    // .	LIST(META)
    // .	.	LIST(GOOD)
    // .	.	.	ONE  "a"
    // .	.	.	FIVE "klmno"
    // .	.	ZERO ""
    // .	.	LIST(BAD )
    // .	.	.	THRE "def"
    // .	TWO  "bc"
    // .	LIST(UGLY)
    // .	.	FOUR "ghij"
    // .	.	SIX  "pqrstu"
}

func dump(r *riff.Reader, indent string) error {
    for {
        chunkID, chunkLen, chunkData, err := r.Next()
        if err == io.EOF {
            return nil
        }
        if err != nil {
            return err
        }
        if chunkID == riff.LIST {
            listType, list, err := riff.NewListReader(chunkLen, chunkData)
            if err != nil {
                return err
            }
            fmt.Printf("%sLIST(%s)\n", indent, listType)
            if err := dump(list, indent+".\t"); err != nil {
                return err
            }
            continue
        }
        b, err := ioutil.ReadAll(chunkData)
        if err != nil {
            return err
        }
        fmt.Printf("%s%s %q\n", indent, chunkID, b)
    }
}

func encodeU32(u uint32) string {
    return string([]byte{
        byte(u >> 0),
        byte(u >> 8),
        byte(u >> 16),
        byte(u >> 24),
    })
}

func encode(chunkID, contents string) string {
    n := len(contents)
    if n&1 == 1 {
        contents += "\x00"
    }
    return chunkID + encodeU32(uint32(n)) + contents
}

func encodeMulti(typ0, typ1 string, chunks ...string) string {
    n := 4
    for _, c := range chunks {
        n += len(c)
    }
    s := typ0 + encodeU32(uint32(n)) + typ1
    for _, c := range chunks {
        s += c
    }
    return s
}

var (
    d0   = encode("ZERO", "")
    d1   = encode("ONE ", "a")
    d2   = encode("TWO ", "bc")
    d3   = encode("THRE", "def")
    d4   = encode("FOUR", "ghij")
    d5   = encode("FIVE", "klmno")
    d6   = encode("SIX ", "pqrstu")
    l0   = encodeMulti("LIST", "GOOD", d1, d5)
    l1   = encodeMulti("LIST", "BAD ", d3)
    l2   = encodeMulti("LIST", "UGLY", d4, d6)
    l01  = encodeMulti("LIST", "META", l0, d0, l1)
    data = encodeMulti("RIFF", "ROOT", d0, d1, l01, d2, l2)
)