wa-lang.org/wazero@v1.0.2/internal/wasm/counts.go (about)

     1  package wasm
     2  
     3  import "fmt"
     4  
     5  // ImportFuncCount returns the possibly empty count of imported functions. This plus SectionElementCount of
     6  // SectionIDFunction is the size of the function index namespace.
     7  func (m *Module) ImportFuncCount() uint32 {
     8  	return m.importCount(ExternTypeFunc)
     9  }
    10  
    11  // ImportTableCount returns the possibly empty count of imported tables. This plus SectionElementCount of SectionIDTable
    12  // is the size of the table index namespace.
    13  func (m *Module) ImportTableCount() uint32 {
    14  	return m.importCount(ExternTypeTable)
    15  }
    16  
    17  // ImportMemoryCount returns the possibly empty count of imported memories. This plus SectionElementCount of
    18  // SectionIDMemory is the size of the memory index namespace.
    19  func (m *Module) ImportMemoryCount() uint32 {
    20  	return m.importCount(ExternTypeMemory) // TODO: once validation happens on decode, this is zero or one.
    21  }
    22  
    23  // ImportGlobalCount returns the possibly empty count of imported globals. This plus SectionElementCount of
    24  // SectionIDGlobal is the size of the global index namespace.
    25  func (m *Module) ImportGlobalCount() uint32 {
    26  	return m.importCount(ExternTypeGlobal)
    27  }
    28  
    29  // importCount returns the count of a specific type of import. This is important because it is easy to mistake the
    30  // length of the import section with the count of a specific kind of import.
    31  func (m *Module) importCount(et ExternType) (res uint32) {
    32  	for _, im := range m.ImportSection {
    33  		if im.Type == et {
    34  			res++
    35  		}
    36  	}
    37  	return
    38  }
    39  
    40  // SectionElementCount returns the count of elements in a given section ID
    41  //
    42  // For example...
    43  // * SectionIDType returns the count of FunctionType
    44  // * SectionIDCustom returns one if the NameSection is present
    45  // * SectionIDHostFunction returns the count of HostFunctionSection
    46  // * SectionIDExport returns the count of unique export names
    47  func (m *Module) SectionElementCount(sectionID SectionID) uint32 { // element as in vector elements!
    48  	switch sectionID {
    49  	case SectionIDCustom:
    50  		if m.NameSection != nil {
    51  			return 1
    52  		}
    53  		return 0
    54  	case SectionIDType:
    55  		return uint32(len(m.TypeSection))
    56  	case SectionIDImport:
    57  		return uint32(len(m.ImportSection))
    58  	case SectionIDFunction:
    59  		return uint32(len(m.FunctionSection))
    60  	case SectionIDTable:
    61  		return uint32(len(m.TableSection))
    62  	case SectionIDMemory:
    63  		if m.MemorySection != nil {
    64  			return 1
    65  		}
    66  		return 0
    67  	case SectionIDGlobal:
    68  		return uint32(len(m.GlobalSection))
    69  	case SectionIDExport:
    70  		return uint32(len(m.ExportSection))
    71  	case SectionIDStart:
    72  		if m.StartSection != nil {
    73  			return 1
    74  		}
    75  		return 0
    76  	case SectionIDElement:
    77  		return uint32(len(m.ElementSection))
    78  	case SectionIDCode:
    79  		return uint32(len(m.CodeSection))
    80  	case SectionIDData:
    81  		return uint32(len(m.DataSection))
    82  	default:
    83  		panic(fmt.Errorf("BUG: unknown section: %d", sectionID))
    84  	}
    85  }